core: Add tests for no float charconv

CMakeLists.txt

@@ -1,6 +1,6 @@
 # Based on: https://gitlab.com/CLIUtils/modern-cmake
 
-cmake_minimum_required(VERSION 3.22)
+cmake_minimum_required(VERSION 3.25)
 project(
         hage
         VERSION 0.1

include/hage/core/charconv.hpp

@@ -22,7 +22,7 @@ from_chars(const std::span<const char> data, IntType& value, const int base = 10
   return std::from_chars(std::to_address(data.begin()), std::to_address(data.end()), value, base);
 }
 
-#if defined __cpp_lib_to_chars
+#ifndef HAGE_NO_FLOAT_CHARCONV
 template<std::floating_point FloatType>
 std::from_chars_result
 from_chars(const char* first,

src/CMakeLists.txt

@@ -41,8 +41,18 @@ set(LOGGING_HEADER_LIST
         "${hage_SOURCE_DIR}/include/hage/logging/console_sink.hpp"
 )
 
+
 add_library(hage_core INTERFACE)
 
+# some compilers don't support the float charconvs yet
+try_compile(HAS_FLOAT_CHARCONV SOURCES ${CMAKE_CURRENT_SOURCE_DIR}/compile_tests/float_charconv.cpp
+        CXX_STANDARD 20 CXX_EXTENSIONS OFF)
+
+if(NOT HAS_FLOAT_CHARCONV)
+    target_compile_definitions(hage_core INTERFACE HAGE_NO_FLOAT_CHARCONV=1)
+endif()
+
+
 target_sources(hage_core INTERFACE ${CORE_HEADER_LIST})
 target_include_directories(hage_core INTERFACE ../include)
 

src/compile_tests/float_charconv.cpp

@@ -0,0 +1,14 @@
+//
+// Created by rhermes on 2024-05-06.
+//
+#include <charconv>
+#include <string>
+
+int
+main()
+{
+  std::string s = "123.3";
+  float x;
+  std::from_chars(s.data(), s.data() + s.size(), x);
+  return 0;
+}

tests/core_charconv_tests.cpp

@@ -1,7 +1,4 @@
 #include <doctest/doctest.h>
-
-#if __has_include(<charconv>)
-
 #include <hage/core/charconv.hpp>
 #include <string>
 
@@ -27,7 +24,7 @@ TEST_CASE("Charconv integer overloads")
   }
 }
 
-#if defined __cpp_lib_to_chars
+#ifndef HAGE_NO_FLOAT_CHARCONV
 
 TEST_CASE("Charconv floats overloads")
 {
@@ -49,6 +46,4 @@ TEST_CASE("Charconv floats overloads")
   }
 }
 #endif
-TEST_SUITE_END();
-
-#endif
+TEST_SUITE_END();