diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 4d1247995..867639527 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -16,7 +16,7 @@ jobs:
       matrix:
         compiler: [clang++-15, g++-12]
     steps:
-    - uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd
+    - uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1
     - name: Install Dependencies
       # Boost must be installed only because the CMake version (3.12) can't
       # detect the installed Boost version (1.69)
@@ -32,12 +32,12 @@ jobs:
   linux-latest:
     name: Linux Latest Config
     needs: [linux-min]
-    runs-on: ubuntu-24.04
+    runs-on: ubuntu-26.04
     strategy:
       matrix:
         compiler: [clang++, g++]
     steps:
-    - uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd
+    - uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1
     - name: Install Dependencies
       # Boost must be installed only because the CMake version (3.12) can't
       # detect the installed Boost version (1.69)
@@ -64,7 +64,7 @@ jobs:
     needs: [linux-min]
     runs-on: windows-2022
     steps:
-    - uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd
+    - uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1
     - name: Run Tests
       shell: powershell
       # Delete the exercises that require Boost to avoid issues with Windows setup.
@@ -80,7 +80,7 @@ jobs:
     needs: [linux-min]
     runs-on: macOS-latest
     steps:
-    - uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd
+    - uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1
     - name: Install Boost
       run: brew install boost
     - name: Run Tests
diff --git a/.github/workflows/format-code.yml b/.github/workflows/format-code.yml
index 2270dffea..5fac99bbc 100644
--- a/.github/workflows/format-code.yml
+++ b/.github/workflows/format-code.yml
@@ -7,7 +7,7 @@ on:
 jobs:
   format:
     name: "Format C++ code"
-    runs-on: ubuntu-22.04
+    runs-on: ubuntu-24.04
     if: github.event.issue.pull_request != '' && (contains(github.event.comment.body, '/format') || contains(github.event.comment.body, '/clang-format'))
     steps:
       - name: "Checkout code"
diff --git a/.github/workflows/hello-world.yml b/.github/workflows/hello-world.yml
index fee42f648..e75d287e1 100644
--- a/.github/workflows/hello-world.yml
+++ b/.github/workflows/hello-world.yml
@@ -19,9 +19,9 @@ on:
 jobs:
   hello-world-fails:
     name: Hello World Fails
-    runs-on: ubuntu-22.04
+    runs-on: ubuntu-24.04
     steps:
-    - uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd
+    - uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1
     - name: Check Hello World Fails
       run: bin/check-hello-world.sh
       env:
diff --git a/.github/workflows/pre-commit.yml b/.github/workflows/pre-commit.yml
index 9977425ec..777d3396c 100644
--- a/.github/workflows/pre-commit.yml
+++ b/.github/workflows/pre-commit.yml
@@ -11,16 +11,14 @@ on:
 jobs:
   pre-commit:
     name: Pre-commit checks
-    runs-on: ubuntu-22.04
+    runs-on: ubuntu-26.04
     steps:
       - name: Checkout code
-        uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd
+        uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1
         with:
           ref: ${{github.event.pull_request.head.sha}}
           repository: ${{github.event.pull_request.head.repo.full_name}}
       - name: Set up Python
-        uses: actions/setup-python@v6
-        with:
-          python-version: "3.10"
+        uses: actions/setup-python@v7
       - name: Run pre-commit checks on PR
         uses: pre-commit/action@v3.0.1
diff --git a/exercises/concept/doctor-data/test/catch.hpp b/exercises/concept/doctor-data/test/catch.hpp
index 36eaeb27f..ff40b4fd6 100644
--- a/exercises/concept/doctor-data/test/catch.hpp
+++ b/exercises/concept/doctor-data/test/catch.hpp
@@ -3175,8 +3175,8 @@ namespace Detail {
 } // end namespace Detail
 
 namespace literals {
-    Detail::Approx operator "" _a(long double val);
-    Detail::Approx operator "" _a(unsigned long long val);
+    Detail::Approx operator ""_a(long double val);
+    Detail::Approx operator ""_a(unsigned long long val);
 } // end namespace literals
 
 template<>
@@ -7911,10 +7911,10 @@ namespace Detail {
 } // end namespace Detail
 
 namespace literals {
-    Detail::Approx operator "" _a(long double val) {
+    Detail::Approx operator ""_a(long double val) {
         return Detail::Approx(val);
     }
-    Detail::Approx operator "" _a(unsigned long long val) {
+    Detail::Approx operator ""_a(unsigned long long val) {
         return Detail::Approx(val);
     }
 } // end namespace literals
diff --git a/exercises/concept/election-day/test/catch.hpp b/exercises/concept/election-day/test/catch.hpp
index 36eaeb27f..ff40b4fd6 100644
--- a/exercises/concept/election-day/test/catch.hpp
+++ b/exercises/concept/election-day/test/catch.hpp
@@ -3175,8 +3175,8 @@ namespace Detail {
 } // end namespace Detail
 
 namespace literals {
-    Detail::Approx operator "" _a(long double val);
-    Detail::Approx operator "" _a(unsigned long long val);
+    Detail::Approx operator ""_a(long double val);
+    Detail::Approx operator ""_a(unsigned long long val);
 } // end namespace literals
 
 template<>
@@ -7911,10 +7911,10 @@ namespace Detail {
 } // end namespace Detail
 
 namespace literals {
-    Detail::Approx operator "" _a(long double val) {
+    Detail::Approx operator ""_a(long double val) {
         return Detail::Approx(val);
     }
-    Detail::Approx operator "" _a(unsigned long long val) {
+    Detail::Approx operator ""_a(unsigned long long val) {
         return Detail::Approx(val);
     }
 } // end namespace literals
diff --git a/exercises/concept/ellens-alien-game/test/catch.hpp b/exercises/concept/ellens-alien-game/test/catch.hpp
index 36eaeb27f..ff40b4fd6 100644
--- a/exercises/concept/ellens-alien-game/test/catch.hpp
+++ b/exercises/concept/ellens-alien-game/test/catch.hpp
@@ -3175,8 +3175,8 @@ namespace Detail {
 } // end namespace Detail
 
 namespace literals {
-    Detail::Approx operator "" _a(long double val);
-    Detail::Approx operator "" _a(unsigned long long val);
+    Detail::Approx operator ""_a(long double val);
+    Detail::Approx operator ""_a(unsigned long long val);
 } // end namespace literals
 
 template<>
@@ -7911,10 +7911,10 @@ namespace Detail {
 } // end namespace Detail
 
 namespace literals {
-    Detail::Approx operator "" _a(long double val) {
+    Detail::Approx operator ""_a(long double val) {
         return Detail::Approx(val);
     }
-    Detail::Approx operator "" _a(unsigned long long val) {
+    Detail::Approx operator ""_a(unsigned long long val) {
         return Detail::Approx(val);
     }
 } // end namespace literals
diff --git a/exercises/concept/freelancer-rates/test/catch.hpp b/exercises/concept/freelancer-rates/test/catch.hpp
index 36eaeb27f..ff40b4fd6 100644
--- a/exercises/concept/freelancer-rates/test/catch.hpp
+++ b/exercises/concept/freelancer-rates/test/catch.hpp
@@ -3175,8 +3175,8 @@ namespace Detail {
 } // end namespace Detail
 
 namespace literals {
-    Detail::Approx operator "" _a(long double val);
-    Detail::Approx operator "" _a(unsigned long long val);
+    Detail::Approx operator ""_a(long double val);
+    Detail::Approx operator ""_a(unsigned long long val);
 } // end namespace literals
 
 template<>
@@ -7911,10 +7911,10 @@ namespace Detail {
 } // end namespace Detail
 
 namespace literals {
-    Detail::Approx operator "" _a(long double val) {
+    Detail::Approx operator ""_a(long double val) {
         return Detail::Approx(val);
     }
-    Detail::Approx operator "" _a(unsigned long long val) {
+    Detail::Approx operator ""_a(unsigned long long val) {
         return Detail::Approx(val);
     }
 } // end namespace literals
diff --git a/exercises/concept/interest-is-interesting/test/catch.hpp b/exercises/concept/interest-is-interesting/test/catch.hpp
index 36eaeb27f..ff40b4fd6 100644
--- a/exercises/concept/interest-is-interesting/test/catch.hpp
+++ b/exercises/concept/interest-is-interesting/test/catch.hpp
@@ -3175,8 +3175,8 @@ namespace Detail {
 } // end namespace Detail
 
 namespace literals {
-    Detail::Approx operator "" _a(long double val);
-    Detail::Approx operator "" _a(unsigned long long val);
+    Detail::Approx operator ""_a(long double val);
+    Detail::Approx operator ""_a(unsigned long long val);
 } // end namespace literals
 
 template<>
@@ -7911,10 +7911,10 @@ namespace Detail {
 } // end namespace Detail
 
 namespace literals {
-    Detail::Approx operator "" _a(long double val) {
+    Detail::Approx operator ""_a(long double val) {
         return Detail::Approx(val);
     }
-    Detail::Approx operator "" _a(unsigned long long val) {
+    Detail::Approx operator ""_a(unsigned long long val) {
         return Detail::Approx(val);
     }
 } // end namespace literals
diff --git a/exercises/concept/lasagna-master/test/catch.hpp b/exercises/concept/lasagna-master/test/catch.hpp
index 36eaeb27f..ff40b4fd6 100644
--- a/exercises/concept/lasagna-master/test/catch.hpp
+++ b/exercises/concept/lasagna-master/test/catch.hpp
@@ -3175,8 +3175,8 @@ namespace Detail {
 } // end namespace Detail
 
 namespace literals {
-    Detail::Approx operator "" _a(long double val);
-    Detail::Approx operator "" _a(unsigned long long val);
+    Detail::Approx operator ""_a(long double val);
+    Detail::Approx operator ""_a(unsigned long long val);
 } // end namespace literals
 
 template<>
@@ -7911,10 +7911,10 @@ namespace Detail {
 } // end namespace Detail
 
 namespace literals {
-    Detail::Approx operator "" _a(long double val) {
+    Detail::Approx operator ""_a(long double val) {
         return Detail::Approx(val);
     }
-    Detail::Approx operator "" _a(unsigned long long val) {
+    Detail::Approx operator ""_a(unsigned long long val) {
         return Detail::Approx(val);
     }
 } // end namespace literals
diff --git a/exercises/concept/lasagna/test/catch.hpp b/exercises/concept/lasagna/test/catch.hpp
index 36eaeb27f..ff40b4fd6 100644
--- a/exercises/concept/lasagna/test/catch.hpp
+++ b/exercises/concept/lasagna/test/catch.hpp
@@ -3175,8 +3175,8 @@ namespace Detail {
 } // end namespace Detail
 
 namespace literals {
-    Detail::Approx operator "" _a(long double val);
-    Detail::Approx operator "" _a(unsigned long long val);
+    Detail::Approx operator ""_a(long double val);
+    Detail::Approx operator ""_a(unsigned long long val);
 } // end namespace literals
 
 template<>
@@ -7911,10 +7911,10 @@ namespace Detail {
 } // end namespace Detail
 
 namespace literals {
-    Detail::Approx operator "" _a(long double val) {
+    Detail::Approx operator ""_a(long double val) {
         return Detail::Approx(val);
     }
-    Detail::Approx operator "" _a(unsigned long long val) {
+    Detail::Approx operator ""_a(unsigned long long val) {
         return Detail::Approx(val);
     }
 } // end namespace literals
diff --git a/exercises/concept/last-will/test/catch.hpp b/exercises/concept/last-will/test/catch.hpp
index 36eaeb27f..ff40b4fd6 100644
--- a/exercises/concept/last-will/test/catch.hpp
+++ b/exercises/concept/last-will/test/catch.hpp
@@ -3175,8 +3175,8 @@ namespace Detail {
 } // end namespace Detail
 
 namespace literals {
-    Detail::Approx operator "" _a(long double val);
-    Detail::Approx operator "" _a(unsigned long long val);
+    Detail::Approx operator ""_a(long double val);
+    Detail::Approx operator ""_a(unsigned long long val);
 } // end namespace literals
 
 template<>
@@ -7911,10 +7911,10 @@ namespace Detail {
 } // end namespace Detail
 
 namespace literals {
-    Detail::Approx operator "" _a(long double val) {
+    Detail::Approx operator ""_a(long double val) {
         return Detail::Approx(val);
     }
-    Detail::Approx operator "" _a(unsigned long long val) {
+    Detail::Approx operator ""_a(unsigned long long val) {
         return Detail::Approx(val);
     }
 } // end namespace literals
diff --git a/exercises/concept/log-levels/test/catch.hpp b/exercises/concept/log-levels/test/catch.hpp
index 36eaeb27f..ff40b4fd6 100644
--- a/exercises/concept/log-levels/test/catch.hpp
+++ b/exercises/concept/log-levels/test/catch.hpp
@@ -3175,8 +3175,8 @@ namespace Detail {
 } // end namespace Detail
 
 namespace literals {
-    Detail::Approx operator "" _a(long double val);
-    Detail::Approx operator "" _a(unsigned long long val);
+    Detail::Approx operator ""_a(long double val);
+    Detail::Approx operator ""_a(unsigned long long val);
 } // end namespace literals
 
 template<>
@@ -7911,10 +7911,10 @@ namespace Detail {
 } // end namespace Detail
 
 namespace literals {
-    Detail::Approx operator "" _a(long double val) {
+    Detail::Approx operator ""_a(long double val) {
         return Detail::Approx(val);
     }
-    Detail::Approx operator "" _a(unsigned long long val) {
+    Detail::Approx operator ""_a(unsigned long long val) {
         return Detail::Approx(val);
     }
 } // end namespace literals
diff --git a/exercises/concept/making-the-grade/test/catch.hpp b/exercises/concept/making-the-grade/test/catch.hpp
index 36eaeb27f..ff40b4fd6 100644
--- a/exercises/concept/making-the-grade/test/catch.hpp
+++ b/exercises/concept/making-the-grade/test/catch.hpp
@@ -3175,8 +3175,8 @@ namespace Detail {
 } // end namespace Detail
 
 namespace literals {
-    Detail::Approx operator "" _a(long double val);
-    Detail::Approx operator "" _a(unsigned long long val);
+    Detail::Approx operator ""_a(long double val);
+    Detail::Approx operator ""_a(unsigned long long val);
 } // end namespace literals
 
 template<>
@@ -7911,10 +7911,10 @@ namespace Detail {
 } // end namespace Detail
 
 namespace literals {
-    Detail::Approx operator "" _a(long double val) {
+    Detail::Approx operator ""_a(long double val) {
         return Detail::Approx(val);
     }
-    Detail::Approx operator "" _a(unsigned long long val) {
+    Detail::Approx operator ""_a(unsigned long long val) {
         return Detail::Approx(val);
     }
 } // end namespace literals
diff --git a/exercises/concept/pacman-rules/test/catch.hpp b/exercises/concept/pacman-rules/test/catch.hpp
index 36eaeb27f..ff40b4fd6 100644
--- a/exercises/concept/pacman-rules/test/catch.hpp
+++ b/exercises/concept/pacman-rules/test/catch.hpp
@@ -3175,8 +3175,8 @@ namespace Detail {
 } // end namespace Detail
 
 namespace literals {
-    Detail::Approx operator "" _a(long double val);
-    Detail::Approx operator "" _a(unsigned long long val);
+    Detail::Approx operator ""_a(long double val);
+    Detail::Approx operator ""_a(unsigned long long val);
 } // end namespace literals
 
 template<>
@@ -7911,10 +7911,10 @@ namespace Detail {
 } // end namespace Detail
 
 namespace literals {
-    Detail::Approx operator "" _a(long double val) {
+    Detail::Approx operator ""_a(long double val) {
         return Detail::Approx(val);
     }
-    Detail::Approx operator "" _a(unsigned long long val) {
+    Detail::Approx operator ""_a(unsigned long long val) {
         return Detail::Approx(val);
     }
 } // end namespace literals
diff --git a/exercises/concept/power-of-troy/test/catch.hpp b/exercises/concept/power-of-troy/test/catch.hpp
index 36eaeb27f..ff40b4fd6 100644
--- a/exercises/concept/power-of-troy/test/catch.hpp
+++ b/exercises/concept/power-of-troy/test/catch.hpp
@@ -3175,8 +3175,8 @@ namespace Detail {
 } // end namespace Detail
 
 namespace literals {
-    Detail::Approx operator "" _a(long double val);
-    Detail::Approx operator "" _a(unsigned long long val);
+    Detail::Approx operator ""_a(long double val);
+    Detail::Approx operator ""_a(unsigned long long val);
 } // end namespace literals
 
 template<>
@@ -7911,10 +7911,10 @@ namespace Detail {
 } // end namespace Detail
 
 namespace literals {
-    Detail::Approx operator "" _a(long double val) {
+    Detail::Approx operator ""_a(long double val) {
         return Detail::Approx(val);
     }
-    Detail::Approx operator "" _a(unsigned long long val) {
+    Detail::Approx operator ""_a(unsigned long long val) {
         return Detail::Approx(val);
     }
 } // end namespace literals
diff --git a/exercises/concept/speedywagon/test/catch.hpp b/exercises/concept/speedywagon/test/catch.hpp
index 36eaeb27f..ff40b4fd6 100644
--- a/exercises/concept/speedywagon/test/catch.hpp
+++ b/exercises/concept/speedywagon/test/catch.hpp
@@ -3175,8 +3175,8 @@ namespace Detail {
 } // end namespace Detail
 
 namespace literals {
-    Detail::Approx operator "" _a(long double val);
-    Detail::Approx operator "" _a(unsigned long long val);
+    Detail::Approx operator ""_a(long double val);
+    Detail::Approx operator ""_a(unsigned long long val);
 } // end namespace literals
 
 template<>
@@ -7911,10 +7911,10 @@ namespace Detail {
 } // end namespace Detail
 
 namespace literals {
-    Detail::Approx operator "" _a(long double val) {
+    Detail::Approx operator ""_a(long double val) {
         return Detail::Approx(val);
     }
-    Detail::Approx operator "" _a(unsigned long long val) {
+    Detail::Approx operator ""_a(unsigned long long val) {
         return Detail::Approx(val);
     }
 } // end namespace literals
diff --git a/exercises/concept/troll-the-trolls/test/catch.hpp b/exercises/concept/troll-the-trolls/test/catch.hpp
index 36eaeb27f..ff40b4fd6 100644
--- a/exercises/concept/troll-the-trolls/test/catch.hpp
+++ b/exercises/concept/troll-the-trolls/test/catch.hpp
@@ -3175,8 +3175,8 @@ namespace Detail {
 } // end namespace Detail
 
 namespace literals {
-    Detail::Approx operator "" _a(long double val);
-    Detail::Approx operator "" _a(unsigned long long val);
+    Detail::Approx operator ""_a(long double val);
+    Detail::Approx operator ""_a(unsigned long long val);
 } // end namespace literals
 
 template<>
@@ -7911,10 +7911,10 @@ namespace Detail {
 } // end namespace Detail
 
 namespace literals {
-    Detail::Approx operator "" _a(long double val) {
+    Detail::Approx operator ""_a(long double val) {
         return Detail::Approx(val);
     }
-    Detail::Approx operator "" _a(unsigned long long val) {
+    Detail::Approx operator ""_a(unsigned long long val) {
         return Detail::Approx(val);
     }
 } // end namespace literals
diff --git a/exercises/concept/vehicle-purchase/test/catch.hpp b/exercises/concept/vehicle-purchase/test/catch.hpp
index 36eaeb27f..ff40b4fd6 100644
--- a/exercises/concept/vehicle-purchase/test/catch.hpp
+++ b/exercises/concept/vehicle-purchase/test/catch.hpp
@@ -3175,8 +3175,8 @@ namespace Detail {
 } // end namespace Detail
 
 namespace literals {
-    Detail::Approx operator "" _a(long double val);
-    Detail::Approx operator "" _a(unsigned long long val);
+    Detail::Approx operator ""_a(long double val);
+    Detail::Approx operator ""_a(unsigned long long val);
 } // end namespace literals
 
 template<>
@@ -7911,10 +7911,10 @@ namespace Detail {
 } // end namespace Detail
 
 namespace literals {
-    Detail::Approx operator "" _a(long double val) {
+    Detail::Approx operator ""_a(long double val) {
         return Detail::Approx(val);
     }
-    Detail::Approx operator "" _a(unsigned long long val) {
+    Detail::Approx operator ""_a(unsigned long long val) {
         return Detail::Approx(val);
     }
 } // end namespace literals
diff --git a/exercises/practice/acronym/test/catch.hpp b/exercises/practice/acronym/test/catch.hpp
index 36eaeb27f..ff40b4fd6 100644
--- a/exercises/practice/acronym/test/catch.hpp
+++ b/exercises/practice/acronym/test/catch.hpp
@@ -3175,8 +3175,8 @@ namespace Detail {
 } // end namespace Detail
 
 namespace literals {
-    Detail::Approx operator "" _a(long double val);
-    Detail::Approx operator "" _a(unsigned long long val);
+    Detail::Approx operator ""_a(long double val);
+    Detail::Approx operator ""_a(unsigned long long val);
 } // end namespace literals
 
 template<>
@@ -7911,10 +7911,10 @@ namespace Detail {
 } // end namespace Detail
 
 namespace literals {
-    Detail::Approx operator "" _a(long double val) {
+    Detail::Approx operator ""_a(long double val) {
         return Detail::Approx(val);
     }
-    Detail::Approx operator "" _a(unsigned long long val) {
+    Detail::Approx operator ""_a(unsigned long long val) {
         return Detail::Approx(val);
     }
 } // end namespace literals
diff --git a/exercises/practice/affine-cipher/test/catch.hpp b/exercises/practice/affine-cipher/test/catch.hpp
index 36eaeb27f..ff40b4fd6 100644
--- a/exercises/practice/affine-cipher/test/catch.hpp
+++ b/exercises/practice/affine-cipher/test/catch.hpp
@@ -3175,8 +3175,8 @@ namespace Detail {
 } // end namespace Detail
 
 namespace literals {
-    Detail::Approx operator "" _a(long double val);
-    Detail::Approx operator "" _a(unsigned long long val);
+    Detail::Approx operator ""_a(long double val);
+    Detail::Approx operator ""_a(unsigned long long val);
 } // end namespace literals
 
 template<>
@@ -7911,10 +7911,10 @@ namespace Detail {
 } // end namespace Detail
 
 namespace literals {
-    Detail::Approx operator "" _a(long double val) {
+    Detail::Approx operator ""_a(long double val) {
         return Detail::Approx(val);
     }
-    Detail::Approx operator "" _a(unsigned long long val) {
+    Detail::Approx operator ""_a(unsigned long long val) {
         return Detail::Approx(val);
     }
 } // end namespace literals
diff --git a/exercises/practice/all-your-base/test/catch.hpp b/exercises/practice/all-your-base/test/catch.hpp
index 36eaeb27f..ff40b4fd6 100644
--- a/exercises/practice/all-your-base/test/catch.hpp
+++ b/exercises/practice/all-your-base/test/catch.hpp
@@ -3175,8 +3175,8 @@ namespace Detail {
 } // end namespace Detail
 
 namespace literals {
-    Detail::Approx operator "" _a(long double val);
-    Detail::Approx operator "" _a(unsigned long long val);
+    Detail::Approx operator ""_a(long double val);
+    Detail::Approx operator ""_a(unsigned long long val);
 } // end namespace literals
 
 template<>
@@ -7911,10 +7911,10 @@ namespace Detail {
 } // end namespace Detail
 
 namespace literals {
-    Detail::Approx operator "" _a(long double val) {
+    Detail::Approx operator ""_a(long double val) {
         return Detail::Approx(val);
     }
-    Detail::Approx operator "" _a(unsigned long long val) {
+    Detail::Approx operator ""_a(unsigned long long val) {
         return Detail::Approx(val);
     }
 } // end namespace literals
diff --git a/exercises/practice/allergies/test/catch.hpp b/exercises/practice/allergies/test/catch.hpp
index 36eaeb27f..ff40b4fd6 100644
--- a/exercises/practice/allergies/test/catch.hpp
+++ b/exercises/practice/allergies/test/catch.hpp
@@ -3175,8 +3175,8 @@ namespace Detail {
 } // end namespace Detail
 
 namespace literals {
-    Detail::Approx operator "" _a(long double val);
-    Detail::Approx operator "" _a(unsigned long long val);
+    Detail::Approx operator ""_a(long double val);
+    Detail::Approx operator ""_a(unsigned long long val);
 } // end namespace literals
 
 template<>
@@ -7911,10 +7911,10 @@ namespace Detail {
 } // end namespace Detail
 
 namespace literals {
-    Detail::Approx operator "" _a(long double val) {
+    Detail::Approx operator ""_a(long double val) {
         return Detail::Approx(val);
     }
-    Detail::Approx operator "" _a(unsigned long long val) {
+    Detail::Approx operator ""_a(unsigned long long val) {
         return Detail::Approx(val);
     }
 } // end namespace literals
diff --git a/exercises/practice/alphametics/test/catch.hpp b/exercises/practice/alphametics/test/catch.hpp
index 36eaeb27f..ff40b4fd6 100644
--- a/exercises/practice/alphametics/test/catch.hpp
+++ b/exercises/practice/alphametics/test/catch.hpp
@@ -3175,8 +3175,8 @@ namespace Detail {
 } // end namespace Detail
 
 namespace literals {
-    Detail::Approx operator "" _a(long double val);
-    Detail::Approx operator "" _a(unsigned long long val);
+    Detail::Approx operator ""_a(long double val);
+    Detail::Approx operator ""_a(unsigned long long val);
 } // end namespace literals
 
 template<>
@@ -7911,10 +7911,10 @@ namespace Detail {
 } // end namespace Detail
 
 namespace literals {
-    Detail::Approx operator "" _a(long double val) {
+    Detail::Approx operator ""_a(long double val) {
         return Detail::Approx(val);
     }
-    Detail::Approx operator "" _a(unsigned long long val) {
+    Detail::Approx operator ""_a(unsigned long long val) {
         return Detail::Approx(val);
     }
 } // end namespace literals
diff --git a/exercises/practice/anagram/.meta/config.json b/exercises/practice/anagram/.meta/config.json
index 20a59ffc0..4b7581e0d 100644
--- a/exercises/practice/anagram/.meta/config.json
+++ b/exercises/practice/anagram/.meta/config.json
@@ -25,7 +25,7 @@
       ".meta/example.h"
     ]
   },
-  "blurb": "Given a word and a list of possible anagrams, select the correct sublist.",
+  "blurb": "Find the words that use the same letters as another word.",
   "source": "Inspired by the Extreme Startup game",
   "source_url": "https://github.com/rchatley/extreme_startup"
 }
diff --git a/exercises/practice/anagram/test/catch.hpp b/exercises/practice/anagram/test/catch.hpp
index 36eaeb27f..ff40b4fd6 100644
--- a/exercises/practice/anagram/test/catch.hpp
+++ b/exercises/practice/anagram/test/catch.hpp
@@ -3175,8 +3175,8 @@ namespace Detail {
 } // end namespace Detail
 
 namespace literals {
-    Detail::Approx operator "" _a(long double val);
-    Detail::Approx operator "" _a(unsigned long long val);
+    Detail::Approx operator ""_a(long double val);
+    Detail::Approx operator ""_a(unsigned long long val);
 } // end namespace literals
 
 template<>
@@ -7911,10 +7911,10 @@ namespace Detail {
 } // end namespace Detail
 
 namespace literals {
-    Detail::Approx operator "" _a(long double val) {
+    Detail::Approx operator ""_a(long double val) {
         return Detail::Approx(val);
     }
-    Detail::Approx operator "" _a(unsigned long long val) {
+    Detail::Approx operator ""_a(unsigned long long val) {
         return Detail::Approx(val);
     }
 } // end namespace literals
diff --git a/exercises/practice/armstrong-numbers/test/catch.hpp b/exercises/practice/armstrong-numbers/test/catch.hpp
index 36eaeb27f..ff40b4fd6 100644
--- a/exercises/practice/armstrong-numbers/test/catch.hpp
+++ b/exercises/practice/armstrong-numbers/test/catch.hpp
@@ -3175,8 +3175,8 @@ namespace Detail {
 } // end namespace Detail
 
 namespace literals {
-    Detail::Approx operator "" _a(long double val);
-    Detail::Approx operator "" _a(unsigned long long val);
+    Detail::Approx operator ""_a(long double val);
+    Detail::Approx operator ""_a(unsigned long long val);
 } // end namespace literals
 
 template<>
@@ -7911,10 +7911,10 @@ namespace Detail {
 } // end namespace Detail
 
 namespace literals {
-    Detail::Approx operator "" _a(long double val) {
+    Detail::Approx operator ""_a(long double val) {
         return Detail::Approx(val);
     }
-    Detail::Approx operator "" _a(unsigned long long val) {
+    Detail::Approx operator ""_a(unsigned long long val) {
         return Detail::Approx(val);
     }
 } // end namespace literals
diff --git a/exercises/practice/atbash-cipher/test/catch.hpp b/exercises/practice/atbash-cipher/test/catch.hpp
index 36eaeb27f..ff40b4fd6 100644
--- a/exercises/practice/atbash-cipher/test/catch.hpp
+++ b/exercises/practice/atbash-cipher/test/catch.hpp
@@ -3175,8 +3175,8 @@ namespace Detail {
 } // end namespace Detail
 
 namespace literals {
-    Detail::Approx operator "" _a(long double val);
-    Detail::Approx operator "" _a(unsigned long long val);
+    Detail::Approx operator ""_a(long double val);
+    Detail::Approx operator ""_a(unsigned long long val);
 } // end namespace literals
 
 template<>
@@ -7911,10 +7911,10 @@ namespace Detail {
 } // end namespace Detail
 
 namespace literals {
-    Detail::Approx operator "" _a(long double val) {
+    Detail::Approx operator ""_a(long double val) {
         return Detail::Approx(val);
     }
-    Detail::Approx operator "" _a(unsigned long long val) {
+    Detail::Approx operator ""_a(unsigned long long val) {
         return Detail::Approx(val);
     }
 } // end namespace literals
diff --git a/exercises/practice/bank-account/test/catch.hpp b/exercises/practice/bank-account/test/catch.hpp
index 36eaeb27f..ff40b4fd6 100644
--- a/exercises/practice/bank-account/test/catch.hpp
+++ b/exercises/practice/bank-account/test/catch.hpp
@@ -3175,8 +3175,8 @@ namespace Detail {
 } // end namespace Detail
 
 namespace literals {
-    Detail::Approx operator "" _a(long double val);
-    Detail::Approx operator "" _a(unsigned long long val);
+    Detail::Approx operator ""_a(long double val);
+    Detail::Approx operator ""_a(unsigned long long val);
 } // end namespace literals
 
 template<>
@@ -7911,10 +7911,10 @@ namespace Detail {
 } // end namespace Detail
 
 namespace literals {
-    Detail::Approx operator "" _a(long double val) {
+    Detail::Approx operator ""_a(long double val) {
         return Detail::Approx(val);
     }
-    Detail::Approx operator "" _a(unsigned long long val) {
+    Detail::Approx operator ""_a(unsigned long long val) {
         return Detail::Approx(val);
     }
 } // end namespace literals
diff --git a/exercises/practice/beer-song/test/catch.hpp b/exercises/practice/beer-song/test/catch.hpp
index 36eaeb27f..ff40b4fd6 100644
--- a/exercises/practice/beer-song/test/catch.hpp
+++ b/exercises/practice/beer-song/test/catch.hpp
@@ -3175,8 +3175,8 @@ namespace Detail {
 } // end namespace Detail
 
 namespace literals {
-    Detail::Approx operator "" _a(long double val);
-    Detail::Approx operator "" _a(unsigned long long val);
+    Detail::Approx operator ""_a(long double val);
+    Detail::Approx operator ""_a(unsigned long long val);
 } // end namespace literals
 
 template<>
@@ -7911,10 +7911,10 @@ namespace Detail {
 } // end namespace Detail
 
 namespace literals {
-    Detail::Approx operator "" _a(long double val) {
+    Detail::Approx operator ""_a(long double val) {
         return Detail::Approx(val);
     }
-    Detail::Approx operator "" _a(unsigned long long val) {
+    Detail::Approx operator ""_a(unsigned long long val) {
         return Detail::Approx(val);
     }
 } // end namespace literals
diff --git a/exercises/practice/binary-search-tree/test/catch.hpp b/exercises/practice/binary-search-tree/test/catch.hpp
index 36eaeb27f..ff40b4fd6 100644
--- a/exercises/practice/binary-search-tree/test/catch.hpp
+++ b/exercises/practice/binary-search-tree/test/catch.hpp
@@ -3175,8 +3175,8 @@ namespace Detail {
 } // end namespace Detail
 
 namespace literals {
-    Detail::Approx operator "" _a(long double val);
-    Detail::Approx operator "" _a(unsigned long long val);
+    Detail::Approx operator ""_a(long double val);
+    Detail::Approx operator ""_a(unsigned long long val);
 } // end namespace literals
 
 template<>
@@ -7911,10 +7911,10 @@ namespace Detail {
 } // end namespace Detail
 
 namespace literals {
-    Detail::Approx operator "" _a(long double val) {
+    Detail::Approx operator ""_a(long double val) {
         return Detail::Approx(val);
     }
-    Detail::Approx operator "" _a(unsigned long long val) {
+    Detail::Approx operator ""_a(unsigned long long val) {
         return Detail::Approx(val);
     }
 } // end namespace literals
diff --git a/exercises/practice/binary-search/test/catch.hpp b/exercises/practice/binary-search/test/catch.hpp
index 36eaeb27f..ff40b4fd6 100644
--- a/exercises/practice/binary-search/test/catch.hpp
+++ b/exercises/practice/binary-search/test/catch.hpp
@@ -3175,8 +3175,8 @@ namespace Detail {
 } // end namespace Detail
 
 namespace literals {
-    Detail::Approx operator "" _a(long double val);
-    Detail::Approx operator "" _a(unsigned long long val);
+    Detail::Approx operator ""_a(long double val);
+    Detail::Approx operator ""_a(unsigned long long val);
 } // end namespace literals
 
 template<>
@@ -7911,10 +7911,10 @@ namespace Detail {
 } // end namespace Detail
 
 namespace literals {
-    Detail::Approx operator "" _a(long double val) {
+    Detail::Approx operator ""_a(long double val) {
         return Detail::Approx(val);
     }
-    Detail::Approx operator "" _a(unsigned long long val) {
+    Detail::Approx operator ""_a(unsigned long long val) {
         return Detail::Approx(val);
     }
 } // end namespace literals
diff --git a/exercises/practice/binary/test/catch.hpp b/exercises/practice/binary/test/catch.hpp
index 36eaeb27f..ff40b4fd6 100644
--- a/exercises/practice/binary/test/catch.hpp
+++ b/exercises/practice/binary/test/catch.hpp
@@ -3175,8 +3175,8 @@ namespace Detail {
 } // end namespace Detail
 
 namespace literals {
-    Detail::Approx operator "" _a(long double val);
-    Detail::Approx operator "" _a(unsigned long long val);
+    Detail::Approx operator ""_a(long double val);
+    Detail::Approx operator ""_a(unsigned long long val);
 } // end namespace literals
 
 template<>
@@ -7911,10 +7911,10 @@ namespace Detail {
 } // end namespace Detail
 
 namespace literals {
-    Detail::Approx operator "" _a(long double val) {
+    Detail::Approx operator ""_a(long double val) {
         return Detail::Approx(val);
     }
-    Detail::Approx operator "" _a(unsigned long long val) {
+    Detail::Approx operator ""_a(unsigned long long val) {
         return Detail::Approx(val);
     }
 } // end namespace literals
diff --git a/exercises/practice/bob/test/catch.hpp b/exercises/practice/bob/test/catch.hpp
index 36eaeb27f..ff40b4fd6 100644
--- a/exercises/practice/bob/test/catch.hpp
+++ b/exercises/practice/bob/test/catch.hpp
@@ -3175,8 +3175,8 @@ namespace Detail {
 } // end namespace Detail
 
 namespace literals {
-    Detail::Approx operator "" _a(long double val);
-    Detail::Approx operator "" _a(unsigned long long val);
+    Detail::Approx operator ""_a(long double val);
+    Detail::Approx operator ""_a(unsigned long long val);
 } // end namespace literals
 
 template<>
@@ -7911,10 +7911,10 @@ namespace Detail {
 } // end namespace Detail
 
 namespace literals {
-    Detail::Approx operator "" _a(long double val) {
+    Detail::Approx operator ""_a(long double val) {
         return Detail::Approx(val);
     }
-    Detail::Approx operator "" _a(unsigned long long val) {
+    Detail::Approx operator ""_a(unsigned long long val) {
         return Detail::Approx(val);
     }
 } // end namespace literals
diff --git a/exercises/practice/circular-buffer/test/catch.hpp b/exercises/practice/circular-buffer/test/catch.hpp
index 36eaeb27f..ff40b4fd6 100644
--- a/exercises/practice/circular-buffer/test/catch.hpp
+++ b/exercises/practice/circular-buffer/test/catch.hpp
@@ -3175,8 +3175,8 @@ namespace Detail {
 } // end namespace Detail
 
 namespace literals {
-    Detail::Approx operator "" _a(long double val);
-    Detail::Approx operator "" _a(unsigned long long val);
+    Detail::Approx operator ""_a(long double val);
+    Detail::Approx operator ""_a(unsigned long long val);
 } // end namespace literals
 
 template<>
@@ -7911,10 +7911,10 @@ namespace Detail {
 } // end namespace Detail
 
 namespace literals {
-    Detail::Approx operator "" _a(long double val) {
+    Detail::Approx operator ""_a(long double val) {
         return Detail::Approx(val);
     }
-    Detail::Approx operator "" _a(unsigned long long val) {
+    Detail::Approx operator ""_a(unsigned long long val) {
         return Detail::Approx(val);
     }
 } // end namespace literals
diff --git a/exercises/practice/clock/test/catch.hpp b/exercises/practice/clock/test/catch.hpp
index 36eaeb27f..ff40b4fd6 100644
--- a/exercises/practice/clock/test/catch.hpp
+++ b/exercises/practice/clock/test/catch.hpp
@@ -3175,8 +3175,8 @@ namespace Detail {
 } // end namespace Detail
 
 namespace literals {
-    Detail::Approx operator "" _a(long double val);
-    Detail::Approx operator "" _a(unsigned long long val);
+    Detail::Approx operator ""_a(long double val);
+    Detail::Approx operator ""_a(unsigned long long val);
 } // end namespace literals
 
 template<>
@@ -7911,10 +7911,10 @@ namespace Detail {
 } // end namespace Detail
 
 namespace literals {
-    Detail::Approx operator "" _a(long double val) {
+    Detail::Approx operator ""_a(long double val) {
         return Detail::Approx(val);
     }
-    Detail::Approx operator "" _a(unsigned long long val) {
+    Detail::Approx operator ""_a(unsigned long long val) {
         return Detail::Approx(val);
     }
 } // end namespace literals
diff --git a/exercises/practice/collatz-conjecture/test/catch.hpp b/exercises/practice/collatz-conjecture/test/catch.hpp
index 36eaeb27f..ff40b4fd6 100644
--- a/exercises/practice/collatz-conjecture/test/catch.hpp
+++ b/exercises/practice/collatz-conjecture/test/catch.hpp
@@ -3175,8 +3175,8 @@ namespace Detail {
 } // end namespace Detail
 
 namespace literals {
-    Detail::Approx operator "" _a(long double val);
-    Detail::Approx operator "" _a(unsigned long long val);
+    Detail::Approx operator ""_a(long double val);
+    Detail::Approx operator ""_a(unsigned long long val);
 } // end namespace literals
 
 template<>
@@ -7911,10 +7911,10 @@ namespace Detail {
 } // end namespace Detail
 
 namespace literals {
-    Detail::Approx operator "" _a(long double val) {
+    Detail::Approx operator ""_a(long double val) {
         return Detail::Approx(val);
     }
-    Detail::Approx operator "" _a(unsigned long long val) {
+    Detail::Approx operator ""_a(unsigned long long val) {
         return Detail::Approx(val);
     }
 } // end namespace literals
diff --git a/exercises/practice/complex-numbers/test/catch_amalgamated.cpp b/exercises/practice/complex-numbers/test/catch_amalgamated.cpp
index eba3f00ac..b48af9055 100644
--- a/exercises/practice/complex-numbers/test/catch_amalgamated.cpp
+++ b/exercises/practice/complex-numbers/test/catch_amalgamated.cpp
@@ -468,10 +468,10 @@ namespace Catch {
     }
 
 namespace literals {
-    Approx operator "" _a(long double val) {
+    Approx operator ""_a(long double val) {
         return Approx(val);
     }
-    Approx operator "" _a(unsigned long long val) {
+    Approx operator ""_a(unsigned long long val) {
         return Approx(val);
     }
 } // end namespace literals
diff --git a/exercises/practice/crypto-square/test/catch.hpp b/exercises/practice/crypto-square/test/catch.hpp
index 36eaeb27f..ff40b4fd6 100644
--- a/exercises/practice/crypto-square/test/catch.hpp
+++ b/exercises/practice/crypto-square/test/catch.hpp
@@ -3175,8 +3175,8 @@ namespace Detail {
 } // end namespace Detail
 
 namespace literals {
-    Detail::Approx operator "" _a(long double val);
-    Detail::Approx operator "" _a(unsigned long long val);
+    Detail::Approx operator ""_a(long double val);
+    Detail::Approx operator ""_a(unsigned long long val);
 } // end namespace literals
 
 template<>
@@ -7911,10 +7911,10 @@ namespace Detail {
 } // end namespace Detail
 
 namespace literals {
-    Detail::Approx operator "" _a(long double val) {
+    Detail::Approx operator ""_a(long double val) {
         return Detail::Approx(val);
     }
-    Detail::Approx operator "" _a(unsigned long long val) {
+    Detail::Approx operator ""_a(unsigned long long val) {
         return Detail::Approx(val);
     }
 } // end namespace literals
diff --git a/exercises/practice/darts/test/catch.hpp b/exercises/practice/darts/test/catch.hpp
index 36eaeb27f..ff40b4fd6 100644
--- a/exercises/practice/darts/test/catch.hpp
+++ b/exercises/practice/darts/test/catch.hpp
@@ -3175,8 +3175,8 @@ namespace Detail {
 } // end namespace Detail
 
 namespace literals {
-    Detail::Approx operator "" _a(long double val);
-    Detail::Approx operator "" _a(unsigned long long val);
+    Detail::Approx operator ""_a(long double val);
+    Detail::Approx operator ""_a(unsigned long long val);
 } // end namespace literals
 
 template<>
@@ -7911,10 +7911,10 @@ namespace Detail {
 } // end namespace Detail
 
 namespace literals {
-    Detail::Approx operator "" _a(long double val) {
+    Detail::Approx operator ""_a(long double val) {
         return Detail::Approx(val);
     }
-    Detail::Approx operator "" _a(unsigned long long val) {
+    Detail::Approx operator ""_a(unsigned long long val) {
         return Detail::Approx(val);
     }
 } // end namespace literals
diff --git a/exercises/practice/diamond/test/catch.hpp b/exercises/practice/diamond/test/catch.hpp
index 36eaeb27f..ff40b4fd6 100644
--- a/exercises/practice/diamond/test/catch.hpp
+++ b/exercises/practice/diamond/test/catch.hpp
@@ -3175,8 +3175,8 @@ namespace Detail {
 } // end namespace Detail
 
 namespace literals {
-    Detail::Approx operator "" _a(long double val);
-    Detail::Approx operator "" _a(unsigned long long val);
+    Detail::Approx operator ""_a(long double val);
+    Detail::Approx operator ""_a(unsigned long long val);
 } // end namespace literals
 
 template<>
@@ -7911,10 +7911,10 @@ namespace Detail {
 } // end namespace Detail
 
 namespace literals {
-    Detail::Approx operator "" _a(long double val) {
+    Detail::Approx operator ""_a(long double val) {
         return Detail::Approx(val);
     }
-    Detail::Approx operator "" _a(unsigned long long val) {
+    Detail::Approx operator ""_a(unsigned long long val) {
         return Detail::Approx(val);
     }
 } // end namespace literals
diff --git a/exercises/practice/difference-of-squares/test/catch.hpp b/exercises/practice/difference-of-squares/test/catch.hpp
index 36eaeb27f..ff40b4fd6 100644
--- a/exercises/practice/difference-of-squares/test/catch.hpp
+++ b/exercises/practice/difference-of-squares/test/catch.hpp
@@ -3175,8 +3175,8 @@ namespace Detail {
 } // end namespace Detail
 
 namespace literals {
-    Detail::Approx operator "" _a(long double val);
-    Detail::Approx operator "" _a(unsigned long long val);
+    Detail::Approx operator ""_a(long double val);
+    Detail::Approx operator ""_a(unsigned long long val);
 } // end namespace literals
 
 template<>
@@ -7911,10 +7911,10 @@ namespace Detail {
 } // end namespace Detail
 
 namespace literals {
-    Detail::Approx operator "" _a(long double val) {
+    Detail::Approx operator ""_a(long double val) {
         return Detail::Approx(val);
     }
-    Detail::Approx operator "" _a(unsigned long long val) {
+    Detail::Approx operator ""_a(unsigned long long val) {
         return Detail::Approx(val);
     }
 } // end namespace literals
diff --git a/exercises/practice/dnd-character/test/catch.hpp b/exercises/practice/dnd-character/test/catch.hpp
index 36eaeb27f..ff40b4fd6 100644
--- a/exercises/practice/dnd-character/test/catch.hpp
+++ b/exercises/practice/dnd-character/test/catch.hpp
@@ -3175,8 +3175,8 @@ namespace Detail {
 } // end namespace Detail
 
 namespace literals {
-    Detail::Approx operator "" _a(long double val);
-    Detail::Approx operator "" _a(unsigned long long val);
+    Detail::Approx operator ""_a(long double val);
+    Detail::Approx operator ""_a(unsigned long long val);
 } // end namespace literals
 
 template<>
@@ -7911,10 +7911,10 @@ namespace Detail {
 } // end namespace Detail
 
 namespace literals {
-    Detail::Approx operator "" _a(long double val) {
+    Detail::Approx operator ""_a(long double val) {
         return Detail::Approx(val);
     }
-    Detail::Approx operator "" _a(unsigned long long val) {
+    Detail::Approx operator ""_a(unsigned long long val) {
         return Detail::Approx(val);
     }
 } // end namespace literals
diff --git a/exercises/practice/eliuds-eggs/test/catch.hpp b/exercises/practice/eliuds-eggs/test/catch.hpp
index 36eaeb27f..ff40b4fd6 100644
--- a/exercises/practice/eliuds-eggs/test/catch.hpp
+++ b/exercises/practice/eliuds-eggs/test/catch.hpp
@@ -3175,8 +3175,8 @@ namespace Detail {
 } // end namespace Detail
 
 namespace literals {
-    Detail::Approx operator "" _a(long double val);
-    Detail::Approx operator "" _a(unsigned long long val);
+    Detail::Approx operator ""_a(long double val);
+    Detail::Approx operator ""_a(unsigned long long val);
 } // end namespace literals
 
 template<>
@@ -7911,10 +7911,10 @@ namespace Detail {
 } // end namespace Detail
 
 namespace literals {
-    Detail::Approx operator "" _a(long double val) {
+    Detail::Approx operator ""_a(long double val) {
         return Detail::Approx(val);
     }
-    Detail::Approx operator "" _a(unsigned long long val) {
+    Detail::Approx operator ""_a(unsigned long long val) {
         return Detail::Approx(val);
     }
 } // end namespace literals
diff --git a/exercises/practice/etl/test/catch.hpp b/exercises/practice/etl/test/catch.hpp
index 36eaeb27f..ff40b4fd6 100644
--- a/exercises/practice/etl/test/catch.hpp
+++ b/exercises/practice/etl/test/catch.hpp
@@ -3175,8 +3175,8 @@ namespace Detail {
 } // end namespace Detail
 
 namespace literals {
-    Detail::Approx operator "" _a(long double val);
-    Detail::Approx operator "" _a(unsigned long long val);
+    Detail::Approx operator ""_a(long double val);
+    Detail::Approx operator ""_a(unsigned long long val);
 } // end namespace literals
 
 template<>
@@ -7911,10 +7911,10 @@ namespace Detail {
 } // end namespace Detail
 
 namespace literals {
-    Detail::Approx operator "" _a(long double val) {
+    Detail::Approx operator ""_a(long double val) {
         return Detail::Approx(val);
     }
-    Detail::Approx operator "" _a(unsigned long long val) {
+    Detail::Approx operator ""_a(unsigned long long val) {
         return Detail::Approx(val);
     }
 } // end namespace literals
diff --git a/exercises/practice/flower-field/test/catch.hpp b/exercises/practice/flower-field/test/catch.hpp
index 36eaeb27f..ff40b4fd6 100644
--- a/exercises/practice/flower-field/test/catch.hpp
+++ b/exercises/practice/flower-field/test/catch.hpp
@@ -3175,8 +3175,8 @@ namespace Detail {
 } // end namespace Detail
 
 namespace literals {
-    Detail::Approx operator "" _a(long double val);
-    Detail::Approx operator "" _a(unsigned long long val);
+    Detail::Approx operator ""_a(long double val);
+    Detail::Approx operator ""_a(unsigned long long val);
 } // end namespace literals
 
 template<>
@@ -7911,10 +7911,10 @@ namespace Detail {
 } // end namespace Detail
 
 namespace literals {
-    Detail::Approx operator "" _a(long double val) {
+    Detail::Approx operator ""_a(long double val) {
         return Detail::Approx(val);
     }
-    Detail::Approx operator "" _a(unsigned long long val) {
+    Detail::Approx operator ""_a(unsigned long long val) {
         return Detail::Approx(val);
     }
 } // end namespace literals
diff --git a/exercises/practice/food-chain/test/catch.hpp b/exercises/practice/food-chain/test/catch.hpp
index 36eaeb27f..ff40b4fd6 100644
--- a/exercises/practice/food-chain/test/catch.hpp
+++ b/exercises/practice/food-chain/test/catch.hpp
@@ -3175,8 +3175,8 @@ namespace Detail {
 } // end namespace Detail
 
 namespace literals {
-    Detail::Approx operator "" _a(long double val);
-    Detail::Approx operator "" _a(unsigned long long val);
+    Detail::Approx operator ""_a(long double val);
+    Detail::Approx operator ""_a(unsigned long long val);
 } // end namespace literals
 
 template<>
@@ -7911,10 +7911,10 @@ namespace Detail {
 } // end namespace Detail
 
 namespace literals {
-    Detail::Approx operator "" _a(long double val) {
+    Detail::Approx operator ""_a(long double val) {
         return Detail::Approx(val);
     }
-    Detail::Approx operator "" _a(unsigned long long val) {
+    Detail::Approx operator ""_a(unsigned long long val) {
         return Detail::Approx(val);
     }
 } // end namespace literals
diff --git a/exercises/practice/gigasecond/test/catch.hpp b/exercises/practice/gigasecond/test/catch.hpp
index 36eaeb27f..ff40b4fd6 100644
--- a/exercises/practice/gigasecond/test/catch.hpp
+++ b/exercises/practice/gigasecond/test/catch.hpp
@@ -3175,8 +3175,8 @@ namespace Detail {
 } // end namespace Detail
 
 namespace literals {
-    Detail::Approx operator "" _a(long double val);
-    Detail::Approx operator "" _a(unsigned long long val);
+    Detail::Approx operator ""_a(long double val);
+    Detail::Approx operator ""_a(unsigned long long val);
 } // end namespace literals
 
 template<>
@@ -7911,10 +7911,10 @@ namespace Detail {
 } // end namespace Detail
 
 namespace literals {
-    Detail::Approx operator "" _a(long double val) {
+    Detail::Approx operator ""_a(long double val) {
         return Detail::Approx(val);
     }
-    Detail::Approx operator "" _a(unsigned long long val) {
+    Detail::Approx operator ""_a(unsigned long long val) {
         return Detail::Approx(val);
     }
 } // end namespace literals
diff --git a/exercises/practice/grade-school/test/catch.hpp b/exercises/practice/grade-school/test/catch.hpp
index 36eaeb27f..ff40b4fd6 100644
--- a/exercises/practice/grade-school/test/catch.hpp
+++ b/exercises/practice/grade-school/test/catch.hpp
@@ -3175,8 +3175,8 @@ namespace Detail {
 } // end namespace Detail
 
 namespace literals {
-    Detail::Approx operator "" _a(long double val);
-    Detail::Approx operator "" _a(unsigned long long val);
+    Detail::Approx operator ""_a(long double val);
+    Detail::Approx operator ""_a(unsigned long long val);
 } // end namespace literals
 
 template<>
@@ -7911,10 +7911,10 @@ namespace Detail {
 } // end namespace Detail
 
 namespace literals {
-    Detail::Approx operator "" _a(long double val) {
+    Detail::Approx operator ""_a(long double val) {
         return Detail::Approx(val);
     }
-    Detail::Approx operator "" _a(unsigned long long val) {
+    Detail::Approx operator ""_a(unsigned long long val) {
         return Detail::Approx(val);
     }
 } // end namespace literals
diff --git a/exercises/practice/grains/test/catch.hpp b/exercises/practice/grains/test/catch.hpp
index 36eaeb27f..ff40b4fd6 100644
--- a/exercises/practice/grains/test/catch.hpp
+++ b/exercises/practice/grains/test/catch.hpp
@@ -3175,8 +3175,8 @@ namespace Detail {
 } // end namespace Detail
 
 namespace literals {
-    Detail::Approx operator "" _a(long double val);
-    Detail::Approx operator "" _a(unsigned long long val);
+    Detail::Approx operator ""_a(long double val);
+    Detail::Approx operator ""_a(unsigned long long val);
 } // end namespace literals
 
 template<>
@@ -7911,10 +7911,10 @@ namespace Detail {
 } // end namespace Detail
 
 namespace literals {
-    Detail::Approx operator "" _a(long double val) {
+    Detail::Approx operator ""_a(long double val) {
         return Detail::Approx(val);
     }
-    Detail::Approx operator "" _a(unsigned long long val) {
+    Detail::Approx operator ""_a(unsigned long long val) {
         return Detail::Approx(val);
     }
 } // end namespace literals
diff --git a/exercises/practice/hamming/test/catch.hpp b/exercises/practice/hamming/test/catch.hpp
index 36eaeb27f..ff40b4fd6 100644
--- a/exercises/practice/hamming/test/catch.hpp
+++ b/exercises/practice/hamming/test/catch.hpp
@@ -3175,8 +3175,8 @@ namespace Detail {
 } // end namespace Detail
 
 namespace literals {
-    Detail::Approx operator "" _a(long double val);
-    Detail::Approx operator "" _a(unsigned long long val);
+    Detail::Approx operator ""_a(long double val);
+    Detail::Approx operator ""_a(unsigned long long val);
 } // end namespace literals
 
 template<>
@@ -7911,10 +7911,10 @@ namespace Detail {
 } // end namespace Detail
 
 namespace literals {
-    Detail::Approx operator "" _a(long double val) {
+    Detail::Approx operator ""_a(long double val) {
         return Detail::Approx(val);
     }
-    Detail::Approx operator "" _a(unsigned long long val) {
+    Detail::Approx operator ""_a(unsigned long long val) {
         return Detail::Approx(val);
     }
 } // end namespace literals
diff --git a/exercises/practice/hello-world/test/catch.hpp b/exercises/practice/hello-world/test/catch.hpp
index 36eaeb27f..ff40b4fd6 100644
--- a/exercises/practice/hello-world/test/catch.hpp
+++ b/exercises/practice/hello-world/test/catch.hpp
@@ -3175,8 +3175,8 @@ namespace Detail {
 } // end namespace Detail
 
 namespace literals {
-    Detail::Approx operator "" _a(long double val);
-    Detail::Approx operator "" _a(unsigned long long val);
+    Detail::Approx operator ""_a(long double val);
+    Detail::Approx operator ""_a(unsigned long long val);
 } // end namespace literals
 
 template<>
@@ -7911,10 +7911,10 @@ namespace Detail {
 } // end namespace Detail
 
 namespace literals {
-    Detail::Approx operator "" _a(long double val) {
+    Detail::Approx operator ""_a(long double val) {
         return Detail::Approx(val);
     }
-    Detail::Approx operator "" _a(unsigned long long val) {
+    Detail::Approx operator ""_a(unsigned long long val) {
         return Detail::Approx(val);
     }
 } // end namespace literals
diff --git a/exercises/practice/hexadecimal/test/catch.hpp b/exercises/practice/hexadecimal/test/catch.hpp
index 36eaeb27f..ff40b4fd6 100644
--- a/exercises/practice/hexadecimal/test/catch.hpp
+++ b/exercises/practice/hexadecimal/test/catch.hpp
@@ -3175,8 +3175,8 @@ namespace Detail {
 } // end namespace Detail
 
 namespace literals {
-    Detail::Approx operator "" _a(long double val);
-    Detail::Approx operator "" _a(unsigned long long val);
+    Detail::Approx operator ""_a(long double val);
+    Detail::Approx operator ""_a(unsigned long long val);
 } // end namespace literals
 
 template<>
@@ -7911,10 +7911,10 @@ namespace Detail {
 } // end namespace Detail
 
 namespace literals {
-    Detail::Approx operator "" _a(long double val) {
+    Detail::Approx operator ""_a(long double val) {
         return Detail::Approx(val);
     }
-    Detail::Approx operator "" _a(unsigned long long val) {
+    Detail::Approx operator ""_a(unsigned long long val) {
         return Detail::Approx(val);
     }
 } // end namespace literals
diff --git a/exercises/practice/high-scores/test/catch.hpp b/exercises/practice/high-scores/test/catch.hpp
index 36eaeb27f..ff40b4fd6 100644
--- a/exercises/practice/high-scores/test/catch.hpp
+++ b/exercises/practice/high-scores/test/catch.hpp
@@ -3175,8 +3175,8 @@ namespace Detail {
 } // end namespace Detail
 
 namespace literals {
-    Detail::Approx operator "" _a(long double val);
-    Detail::Approx operator "" _a(unsigned long long val);
+    Detail::Approx operator ""_a(long double val);
+    Detail::Approx operator ""_a(unsigned long long val);
 } // end namespace literals
 
 template<>
@@ -7911,10 +7911,10 @@ namespace Detail {
 } // end namespace Detail
 
 namespace literals {
-    Detail::Approx operator "" _a(long double val) {
+    Detail::Approx operator ""_a(long double val) {
         return Detail::Approx(val);
     }
-    Detail::Approx operator "" _a(unsigned long long val) {
+    Detail::Approx operator ""_a(unsigned long long val) {
         return Detail::Approx(val);
     }
 } // end namespace literals
diff --git a/exercises/practice/isbn-verifier/test/catch.hpp b/exercises/practice/isbn-verifier/test/catch.hpp
index 36eaeb27f..ff40b4fd6 100644
--- a/exercises/practice/isbn-verifier/test/catch.hpp
+++ b/exercises/practice/isbn-verifier/test/catch.hpp
@@ -3175,8 +3175,8 @@ namespace Detail {
 } // end namespace Detail
 
 namespace literals {
-    Detail::Approx operator "" _a(long double val);
-    Detail::Approx operator "" _a(unsigned long long val);
+    Detail::Approx operator ""_a(long double val);
+    Detail::Approx operator ""_a(unsigned long long val);
 } // end namespace literals
 
 template<>
@@ -7911,10 +7911,10 @@ namespace Detail {
 } // end namespace Detail
 
 namespace literals {
-    Detail::Approx operator "" _a(long double val) {
+    Detail::Approx operator ""_a(long double val) {
         return Detail::Approx(val);
     }
-    Detail::Approx operator "" _a(unsigned long long val) {
+    Detail::Approx operator ""_a(unsigned long long val) {
         return Detail::Approx(val);
     }
 } // end namespace literals
diff --git a/exercises/practice/isogram/.meta/config.json b/exercises/practice/isogram/.meta/config.json
index edc754c17..7215852a9 100644
--- a/exercises/practice/isogram/.meta/config.json
+++ b/exercises/practice/isogram/.meta/config.json
@@ -20,7 +20,7 @@
       ".meta/example.h"
     ]
   },
-  "blurb": "Determine if a word or phrase is an isogram.",
+  "blurb": "Determine whether a phrase is an isogram, a word with no repeated letters.",
   "source": "Wikipedia",
   "source_url": "https://en.wikipedia.org/wiki/Isogram"
 }
diff --git a/exercises/practice/isogram/test/catch.hpp b/exercises/practice/isogram/test/catch.hpp
index 36eaeb27f..ff40b4fd6 100644
--- a/exercises/practice/isogram/test/catch.hpp
+++ b/exercises/practice/isogram/test/catch.hpp
@@ -3175,8 +3175,8 @@ namespace Detail {
 } // end namespace Detail
 
 namespace literals {
-    Detail::Approx operator "" _a(long double val);
-    Detail::Approx operator "" _a(unsigned long long val);
+    Detail::Approx operator ""_a(long double val);
+    Detail::Approx operator ""_a(unsigned long long val);
 } // end namespace literals
 
 template<>
@@ -7911,10 +7911,10 @@ namespace Detail {
 } // end namespace Detail
 
 namespace literals {
-    Detail::Approx operator "" _a(long double val) {
+    Detail::Approx operator ""_a(long double val) {
         return Detail::Approx(val);
     }
-    Detail::Approx operator "" _a(unsigned long long val) {
+    Detail::Approx operator ""_a(unsigned long long val) {
         return Detail::Approx(val);
     }
 } // end namespace literals
diff --git a/exercises/practice/kindergarten-garden/test/catch.hpp b/exercises/practice/kindergarten-garden/test/catch.hpp
index 36eaeb27f..ff40b4fd6 100644
--- a/exercises/practice/kindergarten-garden/test/catch.hpp
+++ b/exercises/practice/kindergarten-garden/test/catch.hpp
@@ -3175,8 +3175,8 @@ namespace Detail {
 } // end namespace Detail
 
 namespace literals {
-    Detail::Approx operator "" _a(long double val);
-    Detail::Approx operator "" _a(unsigned long long val);
+    Detail::Approx operator ""_a(long double val);
+    Detail::Approx operator ""_a(unsigned long long val);
 } // end namespace literals
 
 template<>
@@ -7911,10 +7911,10 @@ namespace Detail {
 } // end namespace Detail
 
 namespace literals {
-    Detail::Approx operator "" _a(long double val) {
+    Detail::Approx operator ""_a(long double val) {
         return Detail::Approx(val);
     }
-    Detail::Approx operator "" _a(unsigned long long val) {
+    Detail::Approx operator ""_a(unsigned long long val) {
         return Detail::Approx(val);
     }
 } // end namespace literals
diff --git a/exercises/practice/knapsack/test/catch.hpp b/exercises/practice/knapsack/test/catch.hpp
index 36eaeb27f..ff40b4fd6 100644
--- a/exercises/practice/knapsack/test/catch.hpp
+++ b/exercises/practice/knapsack/test/catch.hpp
@@ -3175,8 +3175,8 @@ namespace Detail {
 } // end namespace Detail
 
 namespace literals {
-    Detail::Approx operator "" _a(long double val);
-    Detail::Approx operator "" _a(unsigned long long val);
+    Detail::Approx operator ""_a(long double val);
+    Detail::Approx operator ""_a(unsigned long long val);
 } // end namespace literals
 
 template<>
@@ -7911,10 +7911,10 @@ namespace Detail {
 } // end namespace Detail
 
 namespace literals {
-    Detail::Approx operator "" _a(long double val) {
+    Detail::Approx operator ""_a(long double val) {
         return Detail::Approx(val);
     }
-    Detail::Approx operator "" _a(unsigned long long val) {
+    Detail::Approx operator ""_a(unsigned long long val) {
         return Detail::Approx(val);
     }
 } // end namespace literals
diff --git a/exercises/practice/largest-series-product/test/catch.hpp b/exercises/practice/largest-series-product/test/catch.hpp
index 36eaeb27f..ff40b4fd6 100644
--- a/exercises/practice/largest-series-product/test/catch.hpp
+++ b/exercises/practice/largest-series-product/test/catch.hpp
@@ -3175,8 +3175,8 @@ namespace Detail {
 } // end namespace Detail
 
 namespace literals {
-    Detail::Approx operator "" _a(long double val);
-    Detail::Approx operator "" _a(unsigned long long val);
+    Detail::Approx operator ""_a(long double val);
+    Detail::Approx operator ""_a(unsigned long long val);
 } // end namespace literals
 
 template<>
@@ -7911,10 +7911,10 @@ namespace Detail {
 } // end namespace Detail
 
 namespace literals {
-    Detail::Approx operator "" _a(long double val) {
+    Detail::Approx operator ""_a(long double val) {
         return Detail::Approx(val);
     }
-    Detail::Approx operator "" _a(unsigned long long val) {
+    Detail::Approx operator ""_a(unsigned long long val) {
         return Detail::Approx(val);
     }
 } // end namespace literals
diff --git a/exercises/practice/leap/test/catch.hpp b/exercises/practice/leap/test/catch.hpp
index 36eaeb27f..ff40b4fd6 100644
--- a/exercises/practice/leap/test/catch.hpp
+++ b/exercises/practice/leap/test/catch.hpp
@@ -3175,8 +3175,8 @@ namespace Detail {
 } // end namespace Detail
 
 namespace literals {
-    Detail::Approx operator "" _a(long double val);
-    Detail::Approx operator "" _a(unsigned long long val);
+    Detail::Approx operator ""_a(long double val);
+    Detail::Approx operator ""_a(unsigned long long val);
 } // end namespace literals
 
 template<>
@@ -7911,10 +7911,10 @@ namespace Detail {
 } // end namespace Detail
 
 namespace literals {
-    Detail::Approx operator "" _a(long double val) {
+    Detail::Approx operator ""_a(long double val) {
         return Detail::Approx(val);
     }
-    Detail::Approx operator "" _a(unsigned long long val) {
+    Detail::Approx operator ""_a(unsigned long long val) {
         return Detail::Approx(val);
     }
 } // end namespace literals
diff --git a/exercises/practice/linked-list/test/catch.hpp b/exercises/practice/linked-list/test/catch.hpp
index 36eaeb27f..ff40b4fd6 100644
--- a/exercises/practice/linked-list/test/catch.hpp
+++ b/exercises/practice/linked-list/test/catch.hpp
@@ -3175,8 +3175,8 @@ namespace Detail {
 } // end namespace Detail
 
 namespace literals {
-    Detail::Approx operator "" _a(long double val);
-    Detail::Approx operator "" _a(unsigned long long val);
+    Detail::Approx operator ""_a(long double val);
+    Detail::Approx operator ""_a(unsigned long long val);
 } // end namespace literals
 
 template<>
@@ -7911,10 +7911,10 @@ namespace Detail {
 } // end namespace Detail
 
 namespace literals {
-    Detail::Approx operator "" _a(long double val) {
+    Detail::Approx operator ""_a(long double val) {
         return Detail::Approx(val);
     }
-    Detail::Approx operator "" _a(unsigned long long val) {
+    Detail::Approx operator ""_a(unsigned long long val) {
         return Detail::Approx(val);
     }
 } // end namespace literals
diff --git a/exercises/practice/list-ops/test/catch.hpp b/exercises/practice/list-ops/test/catch.hpp
index 36eaeb27f..ff40b4fd6 100644
--- a/exercises/practice/list-ops/test/catch.hpp
+++ b/exercises/practice/list-ops/test/catch.hpp
@@ -3175,8 +3175,8 @@ namespace Detail {
 } // end namespace Detail
 
 namespace literals {
-    Detail::Approx operator "" _a(long double val);
-    Detail::Approx operator "" _a(unsigned long long val);
+    Detail::Approx operator ""_a(long double val);
+    Detail::Approx operator ""_a(unsigned long long val);
 } // end namespace literals
 
 template<>
@@ -7911,10 +7911,10 @@ namespace Detail {
 } // end namespace Detail
 
 namespace literals {
-    Detail::Approx operator "" _a(long double val) {
+    Detail::Approx operator ""_a(long double val) {
         return Detail::Approx(val);
     }
-    Detail::Approx operator "" _a(unsigned long long val) {
+    Detail::Approx operator ""_a(unsigned long long val) {
         return Detail::Approx(val);
     }
 } // end namespace literals
diff --git a/exercises/practice/luhn/test/catch.hpp b/exercises/practice/luhn/test/catch.hpp
index 36eaeb27f..ff40b4fd6 100644
--- a/exercises/practice/luhn/test/catch.hpp
+++ b/exercises/practice/luhn/test/catch.hpp
@@ -3175,8 +3175,8 @@ namespace Detail {
 } // end namespace Detail
 
 namespace literals {
-    Detail::Approx operator "" _a(long double val);
-    Detail::Approx operator "" _a(unsigned long long val);
+    Detail::Approx operator ""_a(long double val);
+    Detail::Approx operator ""_a(unsigned long long val);
 } // end namespace literals
 
 template<>
@@ -7911,10 +7911,10 @@ namespace Detail {
 } // end namespace Detail
 
 namespace literals {
-    Detail::Approx operator "" _a(long double val) {
+    Detail::Approx operator ""_a(long double val) {
         return Detail::Approx(val);
     }
-    Detail::Approx operator "" _a(unsigned long long val) {
+    Detail::Approx operator ""_a(unsigned long long val) {
         return Detail::Approx(val);
     }
 } // end namespace literals
diff --git a/exercises/practice/matching-brackets/test/catch.hpp b/exercises/practice/matching-brackets/test/catch.hpp
index 36eaeb27f..ff40b4fd6 100644
--- a/exercises/practice/matching-brackets/test/catch.hpp
+++ b/exercises/practice/matching-brackets/test/catch.hpp
@@ -3175,8 +3175,8 @@ namespace Detail {
 } // end namespace Detail
 
 namespace literals {
-    Detail::Approx operator "" _a(long double val);
-    Detail::Approx operator "" _a(unsigned long long val);
+    Detail::Approx operator ""_a(long double val);
+    Detail::Approx operator ""_a(unsigned long long val);
 } // end namespace literals
 
 template<>
@@ -7911,10 +7911,10 @@ namespace Detail {
 } // end namespace Detail
 
 namespace literals {
-    Detail::Approx operator "" _a(long double val) {
+    Detail::Approx operator ""_a(long double val) {
         return Detail::Approx(val);
     }
-    Detail::Approx operator "" _a(unsigned long long val) {
+    Detail::Approx operator ""_a(unsigned long long val) {
         return Detail::Approx(val);
     }
 } // end namespace literals
diff --git a/exercises/practice/meetup/test/catch.hpp b/exercises/practice/meetup/test/catch.hpp
index 36eaeb27f..ff40b4fd6 100644
--- a/exercises/practice/meetup/test/catch.hpp
+++ b/exercises/practice/meetup/test/catch.hpp
@@ -3175,8 +3175,8 @@ namespace Detail {
 } // end namespace Detail
 
 namespace literals {
-    Detail::Approx operator "" _a(long double val);
-    Detail::Approx operator "" _a(unsigned long long val);
+    Detail::Approx operator ""_a(long double val);
+    Detail::Approx operator ""_a(unsigned long long val);
 } // end namespace literals
 
 template<>
@@ -7911,10 +7911,10 @@ namespace Detail {
 } // end namespace Detail
 
 namespace literals {
-    Detail::Approx operator "" _a(long double val) {
+    Detail::Approx operator ""_a(long double val) {
         return Detail::Approx(val);
     }
-    Detail::Approx operator "" _a(unsigned long long val) {
+    Detail::Approx operator ""_a(unsigned long long val) {
         return Detail::Approx(val);
     }
 } // end namespace literals
diff --git a/exercises/practice/minesweeper/test/catch.hpp b/exercises/practice/minesweeper/test/catch.hpp
index 36eaeb27f..ff40b4fd6 100644
--- a/exercises/practice/minesweeper/test/catch.hpp
+++ b/exercises/practice/minesweeper/test/catch.hpp
@@ -3175,8 +3175,8 @@ namespace Detail {
 } // end namespace Detail
 
 namespace literals {
-    Detail::Approx operator "" _a(long double val);
-    Detail::Approx operator "" _a(unsigned long long val);
+    Detail::Approx operator ""_a(long double val);
+    Detail::Approx operator ""_a(unsigned long long val);
 } // end namespace literals
 
 template<>
@@ -7911,10 +7911,10 @@ namespace Detail {
 } // end namespace Detail
 
 namespace literals {
-    Detail::Approx operator "" _a(long double val) {
+    Detail::Approx operator ""_a(long double val) {
         return Detail::Approx(val);
     }
-    Detail::Approx operator "" _a(unsigned long long val) {
+    Detail::Approx operator ""_a(unsigned long long val) {
         return Detail::Approx(val);
     }
 } // end namespace literals
diff --git a/exercises/practice/nth-prime/test/catch.hpp b/exercises/practice/nth-prime/test/catch.hpp
index 36eaeb27f..ff40b4fd6 100644
--- a/exercises/practice/nth-prime/test/catch.hpp
+++ b/exercises/practice/nth-prime/test/catch.hpp
@@ -3175,8 +3175,8 @@ namespace Detail {
 } // end namespace Detail
 
 namespace literals {
-    Detail::Approx operator "" _a(long double val);
-    Detail::Approx operator "" _a(unsigned long long val);
+    Detail::Approx operator ""_a(long double val);
+    Detail::Approx operator ""_a(unsigned long long val);
 } // end namespace literals
 
 template<>
@@ -7911,10 +7911,10 @@ namespace Detail {
 } // end namespace Detail
 
 namespace literals {
-    Detail::Approx operator "" _a(long double val) {
+    Detail::Approx operator ""_a(long double val) {
         return Detail::Approx(val);
     }
-    Detail::Approx operator "" _a(unsigned long long val) {
+    Detail::Approx operator ""_a(unsigned long long val) {
         return Detail::Approx(val);
     }
 } // end namespace literals
diff --git a/exercises/practice/nucleotide-count/test/catch.hpp b/exercises/practice/nucleotide-count/test/catch.hpp
index 36eaeb27f..ff40b4fd6 100644
--- a/exercises/practice/nucleotide-count/test/catch.hpp
+++ b/exercises/practice/nucleotide-count/test/catch.hpp
@@ -3175,8 +3175,8 @@ namespace Detail {
 } // end namespace Detail
 
 namespace literals {
-    Detail::Approx operator "" _a(long double val);
-    Detail::Approx operator "" _a(unsigned long long val);
+    Detail::Approx operator ""_a(long double val);
+    Detail::Approx operator ""_a(unsigned long long val);
 } // end namespace literals
 
 template<>
@@ -7911,10 +7911,10 @@ namespace Detail {
 } // end namespace Detail
 
 namespace literals {
-    Detail::Approx operator "" _a(long double val) {
+    Detail::Approx operator ""_a(long double val) {
         return Detail::Approx(val);
     }
-    Detail::Approx operator "" _a(unsigned long long val) {
+    Detail::Approx operator ""_a(unsigned long long val) {
         return Detail::Approx(val);
     }
 } // end namespace literals
diff --git a/exercises/practice/pangram/.meta/config.json b/exercises/practice/pangram/.meta/config.json
index a788744c6..699fcd019 100644
--- a/exercises/practice/pangram/.meta/config.json
+++ b/exercises/practice/pangram/.meta/config.json
@@ -22,7 +22,7 @@
       ".meta/example.h"
     ]
   },
-  "blurb": "Determine if a sentence is a pangram.",
+  "blurb": "Determine whether a phrase uses every letter in the Latin alphabet.",
   "source": "Wikipedia",
   "source_url": "https://en.wikipedia.org/wiki/Pangram"
 }
diff --git a/exercises/practice/pangram/test/catch.hpp b/exercises/practice/pangram/test/catch.hpp
index 36eaeb27f..ff40b4fd6 100644
--- a/exercises/practice/pangram/test/catch.hpp
+++ b/exercises/practice/pangram/test/catch.hpp
@@ -3175,8 +3175,8 @@ namespace Detail {
 } // end namespace Detail
 
 namespace literals {
-    Detail::Approx operator "" _a(long double val);
-    Detail::Approx operator "" _a(unsigned long long val);
+    Detail::Approx operator ""_a(long double val);
+    Detail::Approx operator ""_a(unsigned long long val);
 } // end namespace literals
 
 template<>
@@ -7911,10 +7911,10 @@ namespace Detail {
 } // end namespace Detail
 
 namespace literals {
-    Detail::Approx operator "" _a(long double val) {
+    Detail::Approx operator ""_a(long double val) {
         return Detail::Approx(val);
     }
-    Detail::Approx operator "" _a(unsigned long long val) {
+    Detail::Approx operator ""_a(unsigned long long val) {
         return Detail::Approx(val);
     }
 } // end namespace literals
diff --git a/exercises/practice/parallel-letter-frequency/test/catch.hpp b/exercises/practice/parallel-letter-frequency/test/catch.hpp
index 36eaeb27f..ff40b4fd6 100644
--- a/exercises/practice/parallel-letter-frequency/test/catch.hpp
+++ b/exercises/practice/parallel-letter-frequency/test/catch.hpp
@@ -3175,8 +3175,8 @@ namespace Detail {
 } // end namespace Detail
 
 namespace literals {
-    Detail::Approx operator "" _a(long double val);
-    Detail::Approx operator "" _a(unsigned long long val);
+    Detail::Approx operator ""_a(long double val);
+    Detail::Approx operator ""_a(unsigned long long val);
 } // end namespace literals
 
 template<>
@@ -7911,10 +7911,10 @@ namespace Detail {
 } // end namespace Detail
 
 namespace literals {
-    Detail::Approx operator "" _a(long double val) {
+    Detail::Approx operator ""_a(long double val) {
         return Detail::Approx(val);
     }
-    Detail::Approx operator "" _a(unsigned long long val) {
+    Detail::Approx operator ""_a(unsigned long long val) {
         return Detail::Approx(val);
     }
 } // end namespace literals
diff --git a/exercises/practice/pascals-triangle/test/catch.hpp b/exercises/practice/pascals-triangle/test/catch.hpp
index 36eaeb27f..ff40b4fd6 100644
--- a/exercises/practice/pascals-triangle/test/catch.hpp
+++ b/exercises/practice/pascals-triangle/test/catch.hpp
@@ -3175,8 +3175,8 @@ namespace Detail {
 } // end namespace Detail
 
 namespace literals {
-    Detail::Approx operator "" _a(long double val);
-    Detail::Approx operator "" _a(unsigned long long val);
+    Detail::Approx operator ""_a(long double val);
+    Detail::Approx operator ""_a(unsigned long long val);
 } // end namespace literals
 
 template<>
@@ -7911,10 +7911,10 @@ namespace Detail {
 } // end namespace Detail
 
 namespace literals {
-    Detail::Approx operator "" _a(long double val) {
+    Detail::Approx operator ""_a(long double val) {
         return Detail::Approx(val);
     }
-    Detail::Approx operator "" _a(unsigned long long val) {
+    Detail::Approx operator ""_a(unsigned long long val) {
         return Detail::Approx(val);
     }
 } // end namespace literals
diff --git a/exercises/practice/perfect-numbers/test/catch.hpp b/exercises/practice/perfect-numbers/test/catch.hpp
index 36eaeb27f..ff40b4fd6 100644
--- a/exercises/practice/perfect-numbers/test/catch.hpp
+++ b/exercises/practice/perfect-numbers/test/catch.hpp
@@ -3175,8 +3175,8 @@ namespace Detail {
 } // end namespace Detail
 
 namespace literals {
-    Detail::Approx operator "" _a(long double val);
-    Detail::Approx operator "" _a(unsigned long long val);
+    Detail::Approx operator ""_a(long double val);
+    Detail::Approx operator ""_a(unsigned long long val);
 } // end namespace literals
 
 template<>
@@ -7911,10 +7911,10 @@ namespace Detail {
 } // end namespace Detail
 
 namespace literals {
-    Detail::Approx operator "" _a(long double val) {
+    Detail::Approx operator ""_a(long double val) {
         return Detail::Approx(val);
     }
-    Detail::Approx operator "" _a(unsigned long long val) {
+    Detail::Approx operator ""_a(unsigned long long val) {
         return Detail::Approx(val);
     }
 } // end namespace literals
diff --git a/exercises/practice/phone-number/test/catch.hpp b/exercises/practice/phone-number/test/catch.hpp
index 36eaeb27f..ff40b4fd6 100644
--- a/exercises/practice/phone-number/test/catch.hpp
+++ b/exercises/practice/phone-number/test/catch.hpp
@@ -3175,8 +3175,8 @@ namespace Detail {
 } // end namespace Detail
 
 namespace literals {
-    Detail::Approx operator "" _a(long double val);
-    Detail::Approx operator "" _a(unsigned long long val);
+    Detail::Approx operator ""_a(long double val);
+    Detail::Approx operator ""_a(unsigned long long val);
 } // end namespace literals
 
 template<>
@@ -7911,10 +7911,10 @@ namespace Detail {
 } // end namespace Detail
 
 namespace literals {
-    Detail::Approx operator "" _a(long double val) {
+    Detail::Approx operator ""_a(long double val) {
         return Detail::Approx(val);
     }
-    Detail::Approx operator "" _a(unsigned long long val) {
+    Detail::Approx operator ""_a(unsigned long long val) {
         return Detail::Approx(val);
     }
 } // end namespace literals
diff --git a/exercises/practice/pig-latin/test/catch.hpp b/exercises/practice/pig-latin/test/catch.hpp
index 36eaeb27f..ff40b4fd6 100644
--- a/exercises/practice/pig-latin/test/catch.hpp
+++ b/exercises/practice/pig-latin/test/catch.hpp
@@ -3175,8 +3175,8 @@ namespace Detail {
 } // end namespace Detail
 
 namespace literals {
-    Detail::Approx operator "" _a(long double val);
-    Detail::Approx operator "" _a(unsigned long long val);
+    Detail::Approx operator ""_a(long double val);
+    Detail::Approx operator ""_a(unsigned long long val);
 } // end namespace literals
 
 template<>
@@ -7911,10 +7911,10 @@ namespace Detail {
 } // end namespace Detail
 
 namespace literals {
-    Detail::Approx operator "" _a(long double val) {
+    Detail::Approx operator ""_a(long double val) {
         return Detail::Approx(val);
     }
-    Detail::Approx operator "" _a(unsigned long long val) {
+    Detail::Approx operator ""_a(unsigned long long val) {
         return Detail::Approx(val);
     }
 } // end namespace literals
diff --git a/exercises/practice/prime-factors/test/catch.hpp b/exercises/practice/prime-factors/test/catch.hpp
index 36eaeb27f..ff40b4fd6 100644
--- a/exercises/practice/prime-factors/test/catch.hpp
+++ b/exercises/practice/prime-factors/test/catch.hpp
@@ -3175,8 +3175,8 @@ namespace Detail {
 } // end namespace Detail
 
 namespace literals {
-    Detail::Approx operator "" _a(long double val);
-    Detail::Approx operator "" _a(unsigned long long val);
+    Detail::Approx operator ""_a(long double val);
+    Detail::Approx operator ""_a(unsigned long long val);
 } // end namespace literals
 
 template<>
@@ -7911,10 +7911,10 @@ namespace Detail {
 } // end namespace Detail
 
 namespace literals {
-    Detail::Approx operator "" _a(long double val) {
+    Detail::Approx operator ""_a(long double val) {
         return Detail::Approx(val);
     }
-    Detail::Approx operator "" _a(unsigned long long val) {
+    Detail::Approx operator ""_a(unsigned long long val) {
         return Detail::Approx(val);
     }
 } // end namespace literals
diff --git a/exercises/practice/protein-translation/test/catch.hpp b/exercises/practice/protein-translation/test/catch.hpp
index 36eaeb27f..ff40b4fd6 100644
--- a/exercises/practice/protein-translation/test/catch.hpp
+++ b/exercises/practice/protein-translation/test/catch.hpp
@@ -3175,8 +3175,8 @@ namespace Detail {
 } // end namespace Detail
 
 namespace literals {
-    Detail::Approx operator "" _a(long double val);
-    Detail::Approx operator "" _a(unsigned long long val);
+    Detail::Approx operator ""_a(long double val);
+    Detail::Approx operator ""_a(unsigned long long val);
 } // end namespace literals
 
 template<>
@@ -7911,10 +7911,10 @@ namespace Detail {
 } // end namespace Detail
 
 namespace literals {
-    Detail::Approx operator "" _a(long double val) {
+    Detail::Approx operator ""_a(long double val) {
         return Detail::Approx(val);
     }
-    Detail::Approx operator "" _a(unsigned long long val) {
+    Detail::Approx operator ""_a(unsigned long long val) {
         return Detail::Approx(val);
     }
 } // end namespace literals
diff --git a/exercises/practice/queen-attack/test/catch.hpp b/exercises/practice/queen-attack/test/catch.hpp
index 36eaeb27f..ff40b4fd6 100644
--- a/exercises/practice/queen-attack/test/catch.hpp
+++ b/exercises/practice/queen-attack/test/catch.hpp
@@ -3175,8 +3175,8 @@ namespace Detail {
 } // end namespace Detail
 
 namespace literals {
-    Detail::Approx operator "" _a(long double val);
-    Detail::Approx operator "" _a(unsigned long long val);
+    Detail::Approx operator ""_a(long double val);
+    Detail::Approx operator ""_a(unsigned long long val);
 } // end namespace literals
 
 template<>
@@ -7911,10 +7911,10 @@ namespace Detail {
 } // end namespace Detail
 
 namespace literals {
-    Detail::Approx operator "" _a(long double val) {
+    Detail::Approx operator ""_a(long double val) {
         return Detail::Approx(val);
     }
-    Detail::Approx operator "" _a(unsigned long long val) {
+    Detail::Approx operator ""_a(unsigned long long val) {
         return Detail::Approx(val);
     }
 } // end namespace literals
diff --git a/exercises/practice/rail-fence-cipher/test/catch.hpp b/exercises/practice/rail-fence-cipher/test/catch.hpp
index 36eaeb27f..ff40b4fd6 100644
--- a/exercises/practice/rail-fence-cipher/test/catch.hpp
+++ b/exercises/practice/rail-fence-cipher/test/catch.hpp
@@ -3175,8 +3175,8 @@ namespace Detail {
 } // end namespace Detail
 
 namespace literals {
-    Detail::Approx operator "" _a(long double val);
-    Detail::Approx operator "" _a(unsigned long long val);
+    Detail::Approx operator ""_a(long double val);
+    Detail::Approx operator ""_a(unsigned long long val);
 } // end namespace literals
 
 template<>
@@ -7911,10 +7911,10 @@ namespace Detail {
 } // end namespace Detail
 
 namespace literals {
-    Detail::Approx operator "" _a(long double val) {
+    Detail::Approx operator ""_a(long double val) {
         return Detail::Approx(val);
     }
-    Detail::Approx operator "" _a(unsigned long long val) {
+    Detail::Approx operator ""_a(unsigned long long val) {
         return Detail::Approx(val);
     }
 } // end namespace literals
diff --git a/exercises/practice/raindrops/test/catch.hpp b/exercises/practice/raindrops/test/catch.hpp
index 36eaeb27f..ff40b4fd6 100644
--- a/exercises/practice/raindrops/test/catch.hpp
+++ b/exercises/practice/raindrops/test/catch.hpp
@@ -3175,8 +3175,8 @@ namespace Detail {
 } // end namespace Detail
 
 namespace literals {
-    Detail::Approx operator "" _a(long double val);
-    Detail::Approx operator "" _a(unsigned long long val);
+    Detail::Approx operator ""_a(long double val);
+    Detail::Approx operator ""_a(unsigned long long val);
 } // end namespace literals
 
 template<>
@@ -7911,10 +7911,10 @@ namespace Detail {
 } // end namespace Detail
 
 namespace literals {
-    Detail::Approx operator "" _a(long double val) {
+    Detail::Approx operator ""_a(long double val) {
         return Detail::Approx(val);
     }
-    Detail::Approx operator "" _a(unsigned long long val) {
+    Detail::Approx operator ""_a(unsigned long long val) {
         return Detail::Approx(val);
     }
 } // end namespace literals
diff --git a/exercises/practice/resistor-color-duo/test/catch.hpp b/exercises/practice/resistor-color-duo/test/catch.hpp
index 36eaeb27f..ff40b4fd6 100644
--- a/exercises/practice/resistor-color-duo/test/catch.hpp
+++ b/exercises/practice/resistor-color-duo/test/catch.hpp
@@ -3175,8 +3175,8 @@ namespace Detail {
 } // end namespace Detail
 
 namespace literals {
-    Detail::Approx operator "" _a(long double val);
-    Detail::Approx operator "" _a(unsigned long long val);
+    Detail::Approx operator ""_a(long double val);
+    Detail::Approx operator ""_a(unsigned long long val);
 } // end namespace literals
 
 template<>
@@ -7911,10 +7911,10 @@ namespace Detail {
 } // end namespace Detail
 
 namespace literals {
-    Detail::Approx operator "" _a(long double val) {
+    Detail::Approx operator ""_a(long double val) {
         return Detail::Approx(val);
     }
-    Detail::Approx operator "" _a(unsigned long long val) {
+    Detail::Approx operator ""_a(unsigned long long val) {
         return Detail::Approx(val);
     }
 } // end namespace literals
diff --git a/exercises/practice/resistor-color/test/catch.hpp b/exercises/practice/resistor-color/test/catch.hpp
index 36eaeb27f..ff40b4fd6 100644
--- a/exercises/practice/resistor-color/test/catch.hpp
+++ b/exercises/practice/resistor-color/test/catch.hpp
@@ -3175,8 +3175,8 @@ namespace Detail {
 } // end namespace Detail
 
 namespace literals {
-    Detail::Approx operator "" _a(long double val);
-    Detail::Approx operator "" _a(unsigned long long val);
+    Detail::Approx operator ""_a(long double val);
+    Detail::Approx operator ""_a(unsigned long long val);
 } // end namespace literals
 
 template<>
@@ -7911,10 +7911,10 @@ namespace Detail {
 } // end namespace Detail
 
 namespace literals {
-    Detail::Approx operator "" _a(long double val) {
+    Detail::Approx operator ""_a(long double val) {
         return Detail::Approx(val);
     }
-    Detail::Approx operator "" _a(unsigned long long val) {
+    Detail::Approx operator ""_a(unsigned long long val) {
         return Detail::Approx(val);
     }
 } // end namespace literals
diff --git a/exercises/practice/reverse-string/test/catch.hpp b/exercises/practice/reverse-string/test/catch.hpp
index 36eaeb27f..ff40b4fd6 100644
--- a/exercises/practice/reverse-string/test/catch.hpp
+++ b/exercises/practice/reverse-string/test/catch.hpp
@@ -3175,8 +3175,8 @@ namespace Detail {
 } // end namespace Detail
 
 namespace literals {
-    Detail::Approx operator "" _a(long double val);
-    Detail::Approx operator "" _a(unsigned long long val);
+    Detail::Approx operator ""_a(long double val);
+    Detail::Approx operator ""_a(unsigned long long val);
 } // end namespace literals
 
 template<>
@@ -7911,10 +7911,10 @@ namespace Detail {
 } // end namespace Detail
 
 namespace literals {
-    Detail::Approx operator "" _a(long double val) {
+    Detail::Approx operator ""_a(long double val) {
         return Detail::Approx(val);
     }
-    Detail::Approx operator "" _a(unsigned long long val) {
+    Detail::Approx operator ""_a(unsigned long long val) {
         return Detail::Approx(val);
     }
 } // end namespace literals
diff --git a/exercises/practice/rna-transcription/test/catch.hpp b/exercises/practice/rna-transcription/test/catch.hpp
index 36eaeb27f..ff40b4fd6 100644
--- a/exercises/practice/rna-transcription/test/catch.hpp
+++ b/exercises/practice/rna-transcription/test/catch.hpp
@@ -3175,8 +3175,8 @@ namespace Detail {
 } // end namespace Detail
 
 namespace literals {
-    Detail::Approx operator "" _a(long double val);
-    Detail::Approx operator "" _a(unsigned long long val);
+    Detail::Approx operator ""_a(long double val);
+    Detail::Approx operator ""_a(unsigned long long val);
 } // end namespace literals
 
 template<>
@@ -7911,10 +7911,10 @@ namespace Detail {
 } // end namespace Detail
 
 namespace literals {
-    Detail::Approx operator "" _a(long double val) {
+    Detail::Approx operator ""_a(long double val) {
         return Detail::Approx(val);
     }
-    Detail::Approx operator "" _a(unsigned long long val) {
+    Detail::Approx operator ""_a(unsigned long long val) {
         return Detail::Approx(val);
     }
 } // end namespace literals
diff --git a/exercises/practice/robot-name/test/catch.hpp b/exercises/practice/robot-name/test/catch.hpp
index 36eaeb27f..ff40b4fd6 100644
--- a/exercises/practice/robot-name/test/catch.hpp
+++ b/exercises/practice/robot-name/test/catch.hpp
@@ -3175,8 +3175,8 @@ namespace Detail {
 } // end namespace Detail
 
 namespace literals {
-    Detail::Approx operator "" _a(long double val);
-    Detail::Approx operator "" _a(unsigned long long val);
+    Detail::Approx operator ""_a(long double val);
+    Detail::Approx operator ""_a(unsigned long long val);
 } // end namespace literals
 
 template<>
@@ -7911,10 +7911,10 @@ namespace Detail {
 } // end namespace Detail
 
 namespace literals {
-    Detail::Approx operator "" _a(long double val) {
+    Detail::Approx operator ""_a(long double val) {
         return Detail::Approx(val);
     }
-    Detail::Approx operator "" _a(unsigned long long val) {
+    Detail::Approx operator ""_a(unsigned long long val) {
         return Detail::Approx(val);
     }
 } // end namespace literals
diff --git a/exercises/practice/robot-simulator/test/catch.hpp b/exercises/practice/robot-simulator/test/catch.hpp
index 36eaeb27f..ff40b4fd6 100644
--- a/exercises/practice/robot-simulator/test/catch.hpp
+++ b/exercises/practice/robot-simulator/test/catch.hpp
@@ -3175,8 +3175,8 @@ namespace Detail {
 } // end namespace Detail
 
 namespace literals {
-    Detail::Approx operator "" _a(long double val);
-    Detail::Approx operator "" _a(unsigned long long val);
+    Detail::Approx operator ""_a(long double val);
+    Detail::Approx operator ""_a(unsigned long long val);
 } // end namespace literals
 
 template<>
@@ -7911,10 +7911,10 @@ namespace Detail {
 } // end namespace Detail
 
 namespace literals {
-    Detail::Approx operator "" _a(long double val) {
+    Detail::Approx operator ""_a(long double val) {
         return Detail::Approx(val);
     }
-    Detail::Approx operator "" _a(unsigned long long val) {
+    Detail::Approx operator ""_a(unsigned long long val) {
         return Detail::Approx(val);
     }
 } // end namespace literals
diff --git a/exercises/practice/roman-numerals/test/catch.hpp b/exercises/practice/roman-numerals/test/catch.hpp
index 36eaeb27f..ff40b4fd6 100644
--- a/exercises/practice/roman-numerals/test/catch.hpp
+++ b/exercises/practice/roman-numerals/test/catch.hpp
@@ -3175,8 +3175,8 @@ namespace Detail {
 } // end namespace Detail
 
 namespace literals {
-    Detail::Approx operator "" _a(long double val);
-    Detail::Approx operator "" _a(unsigned long long val);
+    Detail::Approx operator ""_a(long double val);
+    Detail::Approx operator ""_a(unsigned long long val);
 } // end namespace literals
 
 template<>
@@ -7911,10 +7911,10 @@ namespace Detail {
 } // end namespace Detail
 
 namespace literals {
-    Detail::Approx operator "" _a(long double val) {
+    Detail::Approx operator ""_a(long double val) {
         return Detail::Approx(val);
     }
-    Detail::Approx operator "" _a(unsigned long long val) {
+    Detail::Approx operator ""_a(unsigned long long val) {
         return Detail::Approx(val);
     }
 } // end namespace literals
diff --git a/exercises/practice/rotational-cipher/test/catch.hpp b/exercises/practice/rotational-cipher/test/catch.hpp
index 36eaeb27f..ff40b4fd6 100644
--- a/exercises/practice/rotational-cipher/test/catch.hpp
+++ b/exercises/practice/rotational-cipher/test/catch.hpp
@@ -3175,8 +3175,8 @@ namespace Detail {
 } // end namespace Detail
 
 namespace literals {
-    Detail::Approx operator "" _a(long double val);
-    Detail::Approx operator "" _a(unsigned long long val);
+    Detail::Approx operator ""_a(long double val);
+    Detail::Approx operator ""_a(unsigned long long val);
 } // end namespace literals
 
 template<>
@@ -7911,10 +7911,10 @@ namespace Detail {
 } // end namespace Detail
 
 namespace literals {
-    Detail::Approx operator "" _a(long double val) {
+    Detail::Approx operator ""_a(long double val) {
         return Detail::Approx(val);
     }
-    Detail::Approx operator "" _a(unsigned long long val) {
+    Detail::Approx operator ""_a(unsigned long long val) {
         return Detail::Approx(val);
     }
 } // end namespace literals
diff --git a/exercises/practice/run-length-encoding/test/catch.hpp b/exercises/practice/run-length-encoding/test/catch.hpp
index 36eaeb27f..ff40b4fd6 100644
--- a/exercises/practice/run-length-encoding/test/catch.hpp
+++ b/exercises/practice/run-length-encoding/test/catch.hpp
@@ -3175,8 +3175,8 @@ namespace Detail {
 } // end namespace Detail
 
 namespace literals {
-    Detail::Approx operator "" _a(long double val);
-    Detail::Approx operator "" _a(unsigned long long val);
+    Detail::Approx operator ""_a(long double val);
+    Detail::Approx operator ""_a(unsigned long long val);
 } // end namespace literals
 
 template<>
@@ -7911,10 +7911,10 @@ namespace Detail {
 } // end namespace Detail
 
 namespace literals {
-    Detail::Approx operator "" _a(long double val) {
+    Detail::Approx operator ""_a(long double val) {
         return Detail::Approx(val);
     }
-    Detail::Approx operator "" _a(unsigned long long val) {
+    Detail::Approx operator ""_a(unsigned long long val) {
         return Detail::Approx(val);
     }
 } // end namespace literals
diff --git a/exercises/practice/say/test/catch.hpp b/exercises/practice/say/test/catch.hpp
index 36eaeb27f..ff40b4fd6 100644
--- a/exercises/practice/say/test/catch.hpp
+++ b/exercises/practice/say/test/catch.hpp
@@ -3175,8 +3175,8 @@ namespace Detail {
 } // end namespace Detail
 
 namespace literals {
-    Detail::Approx operator "" _a(long double val);
-    Detail::Approx operator "" _a(unsigned long long val);
+    Detail::Approx operator ""_a(long double val);
+    Detail::Approx operator ""_a(unsigned long long val);
 } // end namespace literals
 
 template<>
@@ -7911,10 +7911,10 @@ namespace Detail {
 } // end namespace Detail
 
 namespace literals {
-    Detail::Approx operator "" _a(long double val) {
+    Detail::Approx operator ""_a(long double val) {
         return Detail::Approx(val);
     }
-    Detail::Approx operator "" _a(unsigned long long val) {
+    Detail::Approx operator ""_a(unsigned long long val) {
         return Detail::Approx(val);
     }
 } // end namespace literals
diff --git a/exercises/practice/scrabble-score/test/catch.hpp b/exercises/practice/scrabble-score/test/catch.hpp
index 36eaeb27f..ff40b4fd6 100644
--- a/exercises/practice/scrabble-score/test/catch.hpp
+++ b/exercises/practice/scrabble-score/test/catch.hpp
@@ -3175,8 +3175,8 @@ namespace Detail {
 } // end namespace Detail
 
 namespace literals {
-    Detail::Approx operator "" _a(long double val);
-    Detail::Approx operator "" _a(unsigned long long val);
+    Detail::Approx operator ""_a(long double val);
+    Detail::Approx operator ""_a(unsigned long long val);
 } // end namespace literals
 
 template<>
@@ -7911,10 +7911,10 @@ namespace Detail {
 } // end namespace Detail
 
 namespace literals {
-    Detail::Approx operator "" _a(long double val) {
+    Detail::Approx operator ""_a(long double val) {
         return Detail::Approx(val);
     }
-    Detail::Approx operator "" _a(unsigned long long val) {
+    Detail::Approx operator ""_a(unsigned long long val) {
         return Detail::Approx(val);
     }
 } // end namespace literals
diff --git a/exercises/practice/secret-handshake/test/catch.hpp b/exercises/practice/secret-handshake/test/catch.hpp
index 36eaeb27f..ff40b4fd6 100644
--- a/exercises/practice/secret-handshake/test/catch.hpp
+++ b/exercises/practice/secret-handshake/test/catch.hpp
@@ -3175,8 +3175,8 @@ namespace Detail {
 } // end namespace Detail
 
 namespace literals {
-    Detail::Approx operator "" _a(long double val);
-    Detail::Approx operator "" _a(unsigned long long val);
+    Detail::Approx operator ""_a(long double val);
+    Detail::Approx operator ""_a(unsigned long long val);
 } // end namespace literals
 
 template<>
@@ -7911,10 +7911,10 @@ namespace Detail {
 } // end namespace Detail
 
 namespace literals {
-    Detail::Approx operator "" _a(long double val) {
+    Detail::Approx operator ""_a(long double val) {
         return Detail::Approx(val);
     }
-    Detail::Approx operator "" _a(unsigned long long val) {
+    Detail::Approx operator ""_a(unsigned long long val) {
         return Detail::Approx(val);
     }
 } // end namespace literals
diff --git a/exercises/practice/series/test/catch.hpp b/exercises/practice/series/test/catch.hpp
index 36eaeb27f..ff40b4fd6 100644
--- a/exercises/practice/series/test/catch.hpp
+++ b/exercises/practice/series/test/catch.hpp
@@ -3175,8 +3175,8 @@ namespace Detail {
 } // end namespace Detail
 
 namespace literals {
-    Detail::Approx operator "" _a(long double val);
-    Detail::Approx operator "" _a(unsigned long long val);
+    Detail::Approx operator ""_a(long double val);
+    Detail::Approx operator ""_a(unsigned long long val);
 } // end namespace literals
 
 template<>
@@ -7911,10 +7911,10 @@ namespace Detail {
 } // end namespace Detail
 
 namespace literals {
-    Detail::Approx operator "" _a(long double val) {
+    Detail::Approx operator ""_a(long double val) {
         return Detail::Approx(val);
     }
-    Detail::Approx operator "" _a(unsigned long long val) {
+    Detail::Approx operator ""_a(unsigned long long val) {
         return Detail::Approx(val);
     }
 } // end namespace literals
diff --git a/exercises/practice/sieve/test/catch.hpp b/exercises/practice/sieve/test/catch.hpp
index 36eaeb27f..ff40b4fd6 100644
--- a/exercises/practice/sieve/test/catch.hpp
+++ b/exercises/practice/sieve/test/catch.hpp
@@ -3175,8 +3175,8 @@ namespace Detail {
 } // end namespace Detail
 
 namespace literals {
-    Detail::Approx operator "" _a(long double val);
-    Detail::Approx operator "" _a(unsigned long long val);
+    Detail::Approx operator ""_a(long double val);
+    Detail::Approx operator ""_a(unsigned long long val);
 } // end namespace literals
 
 template<>
@@ -7911,10 +7911,10 @@ namespace Detail {
 } // end namespace Detail
 
 namespace literals {
-    Detail::Approx operator "" _a(long double val) {
+    Detail::Approx operator ""_a(long double val) {
         return Detail::Approx(val);
     }
-    Detail::Approx operator "" _a(unsigned long long val) {
+    Detail::Approx operator ""_a(unsigned long long val) {
         return Detail::Approx(val);
     }
 } // end namespace literals
diff --git a/exercises/practice/simple-linked-list/.docs/instructions.append.md b/exercises/practice/simple-linked-list/.docs/instructions.append.md
index 50f3f024a..c15c14194 100644
--- a/exercises/practice/simple-linked-list/.docs/instructions.append.md
+++ b/exercises/practice/simple-linked-list/.docs/instructions.append.md
@@ -1,3 +1,5 @@
+# Instructions append
+
 ## Implementation Hints
 
 We have provided the general structure of a `List` class for you.
diff --git a/exercises/practice/simple-linked-list/test/catch.hpp b/exercises/practice/simple-linked-list/test/catch.hpp
index 36eaeb27f..ff40b4fd6 100644
--- a/exercises/practice/simple-linked-list/test/catch.hpp
+++ b/exercises/practice/simple-linked-list/test/catch.hpp
@@ -3175,8 +3175,8 @@ namespace Detail {
 } // end namespace Detail
 
 namespace literals {
-    Detail::Approx operator "" _a(long double val);
-    Detail::Approx operator "" _a(unsigned long long val);
+    Detail::Approx operator ""_a(long double val);
+    Detail::Approx operator ""_a(unsigned long long val);
 } // end namespace literals
 
 template<>
@@ -7911,10 +7911,10 @@ namespace Detail {
 } // end namespace Detail
 
 namespace literals {
-    Detail::Approx operator "" _a(long double val) {
+    Detail::Approx operator ""_a(long double val) {
         return Detail::Approx(val);
     }
-    Detail::Approx operator "" _a(unsigned long long val) {
+    Detail::Approx operator ""_a(unsigned long long val) {
         return Detail::Approx(val);
     }
 } // end namespace literals
diff --git a/exercises/practice/space-age/test/catch.hpp b/exercises/practice/space-age/test/catch.hpp
index 36eaeb27f..ff40b4fd6 100644
--- a/exercises/practice/space-age/test/catch.hpp
+++ b/exercises/practice/space-age/test/catch.hpp
@@ -3175,8 +3175,8 @@ namespace Detail {
 } // end namespace Detail
 
 namespace literals {
-    Detail::Approx operator "" _a(long double val);
-    Detail::Approx operator "" _a(unsigned long long val);
+    Detail::Approx operator ""_a(long double val);
+    Detail::Approx operator ""_a(unsigned long long val);
 } // end namespace literals
 
 template<>
@@ -7911,10 +7911,10 @@ namespace Detail {
 } // end namespace Detail
 
 namespace literals {
-    Detail::Approx operator "" _a(long double val) {
+    Detail::Approx operator ""_a(long double val) {
         return Detail::Approx(val);
     }
-    Detail::Approx operator "" _a(unsigned long long val) {
+    Detail::Approx operator ""_a(unsigned long long val) {
         return Detail::Approx(val);
     }
 } // end namespace literals
diff --git a/exercises/practice/spiral-matrix/test/catch.hpp b/exercises/practice/spiral-matrix/test/catch.hpp
index 36eaeb27f..ff40b4fd6 100644
--- a/exercises/practice/spiral-matrix/test/catch.hpp
+++ b/exercises/practice/spiral-matrix/test/catch.hpp
@@ -3175,8 +3175,8 @@ namespace Detail {
 } // end namespace Detail
 
 namespace literals {
-    Detail::Approx operator "" _a(long double val);
-    Detail::Approx operator "" _a(unsigned long long val);
+    Detail::Approx operator ""_a(long double val);
+    Detail::Approx operator ""_a(unsigned long long val);
 } // end namespace literals
 
 template<>
@@ -7911,10 +7911,10 @@ namespace Detail {
 } // end namespace Detail
 
 namespace literals {
-    Detail::Approx operator "" _a(long double val) {
+    Detail::Approx operator ""_a(long double val) {
         return Detail::Approx(val);
     }
-    Detail::Approx operator "" _a(unsigned long long val) {
+    Detail::Approx operator ""_a(unsigned long long val) {
         return Detail::Approx(val);
     }
 } // end namespace literals
diff --git a/exercises/practice/sublist/.meta/config.json b/exercises/practice/sublist/.meta/config.json
index ff3fe2fa5..455402a42 100644
--- a/exercises/practice/sublist/.meta/config.json
+++ b/exercises/practice/sublist/.meta/config.json
@@ -15,5 +15,5 @@
       ".meta/example.h"
     ]
   },
-  "blurb": "Write a function to determine if a list is a sublist of another list."
+  "blurb": "Determine if a list is a sublist of another list."
 }
diff --git a/exercises/practice/sublist/test/catch.hpp b/exercises/practice/sublist/test/catch.hpp
index 36eaeb27f..ff40b4fd6 100644
--- a/exercises/practice/sublist/test/catch.hpp
+++ b/exercises/practice/sublist/test/catch.hpp
@@ -3175,8 +3175,8 @@ namespace Detail {
 } // end namespace Detail
 
 namespace literals {
-    Detail::Approx operator "" _a(long double val);
-    Detail::Approx operator "" _a(unsigned long long val);
+    Detail::Approx operator ""_a(long double val);
+    Detail::Approx operator ""_a(unsigned long long val);
 } // end namespace literals
 
 template<>
@@ -7911,10 +7911,10 @@ namespace Detail {
 } // end namespace Detail
 
 namespace literals {
-    Detail::Approx operator "" _a(long double val) {
+    Detail::Approx operator ""_a(long double val) {
         return Detail::Approx(val);
     }
-    Detail::Approx operator "" _a(unsigned long long val) {
+    Detail::Approx operator ""_a(unsigned long long val) {
         return Detail::Approx(val);
     }
 } // end namespace literals
diff --git a/exercises/practice/sum-of-multiples/test/catch.hpp b/exercises/practice/sum-of-multiples/test/catch.hpp
index 36eaeb27f..ff40b4fd6 100644
--- a/exercises/practice/sum-of-multiples/test/catch.hpp
+++ b/exercises/practice/sum-of-multiples/test/catch.hpp
@@ -3175,8 +3175,8 @@ namespace Detail {
 } // end namespace Detail
 
 namespace literals {
-    Detail::Approx operator "" _a(long double val);
-    Detail::Approx operator "" _a(unsigned long long val);
+    Detail::Approx operator ""_a(long double val);
+    Detail::Approx operator ""_a(unsigned long long val);
 } // end namespace literals
 
 template<>
@@ -7911,10 +7911,10 @@ namespace Detail {
 } // end namespace Detail
 
 namespace literals {
-    Detail::Approx operator "" _a(long double val) {
+    Detail::Approx operator ""_a(long double val) {
         return Detail::Approx(val);
     }
-    Detail::Approx operator "" _a(unsigned long long val) {
+    Detail::Approx operator ""_a(unsigned long long val) {
         return Detail::Approx(val);
     }
 } // end namespace literals
diff --git a/exercises/practice/triangle/test/catch.hpp b/exercises/practice/triangle/test/catch.hpp
index 36eaeb27f..ff40b4fd6 100644
--- a/exercises/practice/triangle/test/catch.hpp
+++ b/exercises/practice/triangle/test/catch.hpp
@@ -3175,8 +3175,8 @@ namespace Detail {
 } // end namespace Detail
 
 namespace literals {
-    Detail::Approx operator "" _a(long double val);
-    Detail::Approx operator "" _a(unsigned long long val);
+    Detail::Approx operator ""_a(long double val);
+    Detail::Approx operator ""_a(unsigned long long val);
 } // end namespace literals
 
 template<>
@@ -7911,10 +7911,10 @@ namespace Detail {
 } // end namespace Detail
 
 namespace literals {
-    Detail::Approx operator "" _a(long double val) {
+    Detail::Approx operator ""_a(long double val) {
         return Detail::Approx(val);
     }
-    Detail::Approx operator "" _a(unsigned long long val) {
+    Detail::Approx operator ""_a(unsigned long long val) {
         return Detail::Approx(val);
     }
 } // end namespace literals
diff --git a/exercises/practice/trinary/test/catch.hpp b/exercises/practice/trinary/test/catch.hpp
index 36eaeb27f..ff40b4fd6 100644
--- a/exercises/practice/trinary/test/catch.hpp
+++ b/exercises/practice/trinary/test/catch.hpp
@@ -3175,8 +3175,8 @@ namespace Detail {
 } // end namespace Detail
 
 namespace literals {
-    Detail::Approx operator "" _a(long double val);
-    Detail::Approx operator "" _a(unsigned long long val);
+    Detail::Approx operator ""_a(long double val);
+    Detail::Approx operator ""_a(unsigned long long val);
 } // end namespace literals
 
 template<>
@@ -7911,10 +7911,10 @@ namespace Detail {
 } // end namespace Detail
 
 namespace literals {
-    Detail::Approx operator "" _a(long double val) {
+    Detail::Approx operator ""_a(long double val) {
         return Detail::Approx(val);
     }
-    Detail::Approx operator "" _a(unsigned long long val) {
+    Detail::Approx operator ""_a(unsigned long long val) {
         return Detail::Approx(val);
     }
 } // end namespace literals
diff --git a/exercises/practice/twelve-days/test/catch.hpp b/exercises/practice/twelve-days/test/catch.hpp
index 36eaeb27f..ff40b4fd6 100644
--- a/exercises/practice/twelve-days/test/catch.hpp
+++ b/exercises/practice/twelve-days/test/catch.hpp
@@ -3175,8 +3175,8 @@ namespace Detail {
 } // end namespace Detail
 
 namespace literals {
-    Detail::Approx operator "" _a(long double val);
-    Detail::Approx operator "" _a(unsigned long long val);
+    Detail::Approx operator ""_a(long double val);
+    Detail::Approx operator ""_a(unsigned long long val);
 } // end namespace literals
 
 template<>
@@ -7911,10 +7911,10 @@ namespace Detail {
 } // end namespace Detail
 
 namespace literals {
-    Detail::Approx operator "" _a(long double val) {
+    Detail::Approx operator ""_a(long double val) {
         return Detail::Approx(val);
     }
-    Detail::Approx operator "" _a(unsigned long long val) {
+    Detail::Approx operator ""_a(unsigned long long val) {
         return Detail::Approx(val);
     }
 } // end namespace literals
diff --git a/exercises/practice/two-bucket/test/catch.hpp b/exercises/practice/two-bucket/test/catch.hpp
index 36eaeb27f..ff40b4fd6 100644
--- a/exercises/practice/two-bucket/test/catch.hpp
+++ b/exercises/practice/two-bucket/test/catch.hpp
@@ -3175,8 +3175,8 @@ namespace Detail {
 } // end namespace Detail
 
 namespace literals {
-    Detail::Approx operator "" _a(long double val);
-    Detail::Approx operator "" _a(unsigned long long val);
+    Detail::Approx operator ""_a(long double val);
+    Detail::Approx operator ""_a(unsigned long long val);
 } // end namespace literals
 
 template<>
@@ -7911,10 +7911,10 @@ namespace Detail {
 } // end namespace Detail
 
 namespace literals {
-    Detail::Approx operator "" _a(long double val) {
+    Detail::Approx operator ""_a(long double val) {
         return Detail::Approx(val);
     }
-    Detail::Approx operator "" _a(unsigned long long val) {
+    Detail::Approx operator ""_a(unsigned long long val) {
         return Detail::Approx(val);
     }
 } // end namespace literals
diff --git a/exercises/practice/two-fer/test/catch.hpp b/exercises/practice/two-fer/test/catch.hpp
index 36eaeb27f..ff40b4fd6 100644
--- a/exercises/practice/two-fer/test/catch.hpp
+++ b/exercises/practice/two-fer/test/catch.hpp
@@ -3175,8 +3175,8 @@ namespace Detail {
 } // end namespace Detail
 
 namespace literals {
-    Detail::Approx operator "" _a(long double val);
-    Detail::Approx operator "" _a(unsigned long long val);
+    Detail::Approx operator ""_a(long double val);
+    Detail::Approx operator ""_a(unsigned long long val);
 } // end namespace literals
 
 template<>
@@ -7911,10 +7911,10 @@ namespace Detail {
 } // end namespace Detail
 
 namespace literals {
-    Detail::Approx operator "" _a(long double val) {
+    Detail::Approx operator ""_a(long double val) {
         return Detail::Approx(val);
     }
-    Detail::Approx operator "" _a(unsigned long long val) {
+    Detail::Approx operator ""_a(unsigned long long val) {
         return Detail::Approx(val);
     }
 } // end namespace literals
diff --git a/exercises/practice/word-count/test/catch.hpp b/exercises/practice/word-count/test/catch.hpp
index 36eaeb27f..ff40b4fd6 100644
--- a/exercises/practice/word-count/test/catch.hpp
+++ b/exercises/practice/word-count/test/catch.hpp
@@ -3175,8 +3175,8 @@ namespace Detail {
 } // end namespace Detail
 
 namespace literals {
-    Detail::Approx operator "" _a(long double val);
-    Detail::Approx operator "" _a(unsigned long long val);
+    Detail::Approx operator ""_a(long double val);
+    Detail::Approx operator ""_a(unsigned long long val);
 } // end namespace literals
 
 template<>
@@ -7911,10 +7911,10 @@ namespace Detail {
 } // end namespace Detail
 
 namespace literals {
-    Detail::Approx operator "" _a(long double val) {
+    Detail::Approx operator ""_a(long double val) {
         return Detail::Approx(val);
     }
-    Detail::Approx operator "" _a(unsigned long long val) {
+    Detail::Approx operator ""_a(unsigned long long val) {
         return Detail::Approx(val);
     }
 } // end namespace literals
diff --git a/exercises/practice/yacht/test/catch.hpp b/exercises/practice/yacht/test/catch.hpp
index 36eaeb27f..ff40b4fd6 100644
--- a/exercises/practice/yacht/test/catch.hpp
+++ b/exercises/practice/yacht/test/catch.hpp
@@ -3175,8 +3175,8 @@ namespace Detail {
 } // end namespace Detail
 
 namespace literals {
-    Detail::Approx operator "" _a(long double val);
-    Detail::Approx operator "" _a(unsigned long long val);
+    Detail::Approx operator ""_a(long double val);
+    Detail::Approx operator ""_a(unsigned long long val);
 } // end namespace literals
 
 template<>
@@ -7911,10 +7911,10 @@ namespace Detail {
 } // end namespace Detail
 
 namespace literals {
-    Detail::Approx operator "" _a(long double val) {
+    Detail::Approx operator ""_a(long double val) {
         return Detail::Approx(val);
     }
-    Detail::Approx operator "" _a(unsigned long long val) {
+    Detail::Approx operator ""_a(unsigned long long val) {
         return Detail::Approx(val);
     }
 } // end namespace literals
diff --git a/exercises/practice/zebra-puzzle/test/catch.hpp b/exercises/practice/zebra-puzzle/test/catch.hpp
index 36eaeb27f..ff40b4fd6 100644
--- a/exercises/practice/zebra-puzzle/test/catch.hpp
+++ b/exercises/practice/zebra-puzzle/test/catch.hpp
@@ -3175,8 +3175,8 @@ namespace Detail {
 } // end namespace Detail
 
 namespace literals {
-    Detail::Approx operator "" _a(long double val);
-    Detail::Approx operator "" _a(unsigned long long val);
+    Detail::Approx operator ""_a(long double val);
+    Detail::Approx operator ""_a(unsigned long long val);
 } // end namespace literals
 
 template<>
@@ -7911,10 +7911,10 @@ namespace Detail {
 } // end namespace Detail
 
 namespace literals {
-    Detail::Approx operator "" _a(long double val) {
+    Detail::Approx operator ""_a(long double val) {
         return Detail::Approx(val);
     }
-    Detail::Approx operator "" _a(unsigned long long val) {
+    Detail::Approx operator ""_a(unsigned long long val) {
         return Detail::Approx(val);
     }
 } // end namespace literals
diff --git a/test/catch.hpp b/test/catch.hpp
index 36eaeb27f..ff40b4fd6 100644
--- a/test/catch.hpp
+++ b/test/catch.hpp
@@ -3175,8 +3175,8 @@ namespace Detail {
 } // end namespace Detail
 
 namespace literals {
-    Detail::Approx operator "" _a(long double val);
-    Detail::Approx operator "" _a(unsigned long long val);
+    Detail::Approx operator ""_a(long double val);
+    Detail::Approx operator ""_a(unsigned long long val);
 } // end namespace literals
 
 template<>
@@ -7911,10 +7911,10 @@ namespace Detail {
 } // end namespace Detail
 
 namespace literals {
-    Detail::Approx operator "" _a(long double val) {
+    Detail::Approx operator ""_a(long double val) {
         return Detail::Approx(val);
     }
-    Detail::Approx operator "" _a(unsigned long long val) {
+    Detail::Approx operator ""_a(unsigned long long val) {
         return Detail::Approx(val);
     }
 } // end namespace literals