First pass on C++20-ification of the code

Author: gershnik

.github/workflows/test.yml

@@ -15,7 +15,7 @@ on:
 
 env:
   BUILD_TYPE: Release
-  NDK_VER: 21.3.6528147
+  NDK_VER: 27.2.12479018
   NDK_ARCH: x86_64
   NDK_API: 29
 
@@ -28,31 +28,16 @@ jobs:
         include:
         - os: macos-latest
         - os: windows-latest
-        - os: ubuntu-latest
-          compiler: gcc
-          version: 11
-        - os: ubuntu-latest
-          compiler: gcc
-          version: 12
-        - os: ubuntu-latest
-          compiler: gcc
-          version: 13
-        # See https://github.com/actions/runner-images/issues/8659
-        # - os: ubuntu-latest
-        #   compiler: clang
-        #   version: 13
-        # - os: ubuntu-latest
-        #   compiler: clang
-        #   version: 14
-        - os: ubuntu-latest
-          compiler: clang
-          version: 15
-        - os: ubuntu-latest
-          compiler: clang
-          version: 16
-        - os: ubuntu-latest
-          compiler: clang
-          version: 17
+        - {os: ubuntu-latest, compiler: gcc, version: 11 }
+        - {os: ubuntu-latest, compiler: gcc, version: 12 }
+        - {os: ubuntu-latest, compiler: gcc, version: 13 }
+        - {os: ubuntu-24.04, compiler: gcc, version: 14 }
+        - {os: ubuntu-latest, compiler: clang, version: 13 }
+        - {os: ubuntu-latest, compiler: clang, version: 14 }
+        - {os: ubuntu-latest, compiler: clang, version: 15 }
+        - {os: ubuntu-latest, compiler: clang, version: 16 }
+        - {os: ubuntu-latest, compiler: clang, version: 17 }
+        - {os: ubuntu-latest, compiler: clang, version: 18 }
 
     steps:
     - name: Checkout
@@ -61,16 +46,18 @@ jobs:
     - name: System Setup
       shell: bash
       run: |
-        if [[ '${{ matrix.os }}' == 'ubuntu-latest' ]]; then
+        if [[ '${{ matrix.os }}' == ubuntu-* ]]; then
           if [[ '${{ matrix.compiler }}' == 'clang' ]]; then
             wget https://apt.llvm.org/llvm.sh
             chmod u+x llvm.sh
-            sudo ./llvm.sh ${{ matrix.version }}
+            sudo ./llvm.sh ${{ matrix.version }} 
+            sudo apt-get install -y clang-tools-${{ matrix.version }}
             echo "CC=clang-${{ matrix.version }}" >> $GITHUB_ENV
             echo "CXX=clang++-${{ matrix.version }}" >> $GITHUB_ENV
           fi
 
           if [[ '${{ matrix.compiler }}' == 'gcc' ]]; then
+            sudo add-apt-repository -y ppa:ubuntu-toolchain-r/test
             sudo apt-get update
             sudo apt-get install -y gcc-${{ matrix.version }} g++-${{ matrix.version }}
             echo "CC=gcc-${{ matrix.version }}" >> $GITHUB_ENV
@@ -149,7 +136,7 @@ jobs:
     - name: Set Up Emscripten
       uses: mymindstorm/setup-emsdk@v14
       with:
-        version: 3.1.26
+        version: 3.1.70
         actions-cache-folder: 'emsdk-cache'
 
     - name: Configure

lib/CMakeLists.txt

@@ -32,7 +32,7 @@ set_target_properties(${LIBNAME} PROPERTIES
 
 target_compile_features(${LIBNAME} 
 PUBLIC 
-    cxx_std_17
+    cxx_std_20
 )
 
 target_compile_options(${LIBNAME} 
@@ -105,7 +105,7 @@ set(UTIL_FILES
     ${SRCDIR}/inc/sys_string/impl/util/util.h
     ${SRCDIR}/inc/sys_string/impl/util/char_buffer.h
     ${SRCDIR}/inc/sys_string/impl/util/generic_buffer.h
-    ${SRCDIR}/inc/sys_string/impl/util/cursor.h
+    ${SRCDIR}/inc/sys_string/impl/util/iter_util.h
 
 )
 source_group("Utils" FILES ${UTIL_FILES})

lib/inc/sys_string/config.h

@@ -8,8 +8,18 @@
 #ifndef HEADER_SYS_STRING_CONFIG_H_INCLUDED
 #define HEADER_SYS_STRING_CONFIG_H_INCLUDED
 
-#define SYS_STRING_USE_SPACESHIP_OPERATOR (__cpp_impl_three_way_comparison >= 201907)
-#define SYS_STRING_USE_CHAR8              (__cpp_char8_t >= 201811)
+#if __cplusplus < 202002L || (defined(_MSVC_LANG) && _MSVC_LANG < 202002L)
+    #error This library requires C++20 or above
+#endif
+
+#if __cpp_impl_three_way_comparison < 201907
+    #error This library requires your compiler to support three-way comparison
+#endif
+
+#if __cpp_char8_t < 201811
+    #error This library requires your compiler to support char8_t
+#endif
+
 
 
 #if (defined(__APPLE__) && defined(__MACH__))
@@ -80,45 +90,14 @@
     #include <version>
 #endif
 
-#define SYS_STRING_USE_SPAN               (__cpp_lib_span >= 202002)
-#define SYS_STRING_USE_STD_ENDIAN         (__cpp_lib_endian >= 201907)
-#define SYS_STRING_USE_RANGES             (__cpp_lib_ranges >= 201911)
-
-#if __cpp_lib_constexpr_algorithms >= 201806
-    #define SYS_STRING_CONSTEXPR_ALGO  constexpr
-#else
-    #define SYS_STRING_CONSTEXPR_ALGO
+#if __cpp_lib_endian < 201907
+    #error Your standard library does not support std::endian
 #endif
 
-#if SYS_STRING_USE_STD_ENDIAN
-
-    #include <bit>
-    namespace sysstr
-    {
-        using endian = std::endian; 
-    }
-
-#else
-
-    namespace sysstr
-    {
-        enum class endian
-        {
-        #ifdef _MSC_VER
-            little = 0,
-            big    = 1,
-            native = little
-        #elif defined(__BYTE_ORDER__)
-            little = __ORDER_LITTLE_ENDIAN__,
-            big    = __ORDER_BIG_ENDIAN__,
-            native = __BYTE_ORDER__
-        #else 
-            #error Please define byte order values for your compiler
-        #endif
-        };
-    }
-
+#if __cpp_lib_ranges < 201911
+    #error Your standard library does not support ranges
 #endif
 
 
+
 #endif