More robust tests for C++23

CMakeLists.txt

@@ -1,6 +1,8 @@
 cmake_minimum_required(VERSION 3.9)
 
 project(fast_float VERSION 6.0.0 LANGUAGES CXX)
+set(FASTFLOAT_CXX_STANDARD 11 CACHE STRING "the C++ standard to use for fastfloat")
+set(CMAKE_CXX_STANDARD ${FASTFLOAT_CXX_STANDARD})
 option(FASTFLOAT_TEST "Enable tests" OFF)
 if(FASTFLOAT_TEST)
   enable_testing()

tests/CMakeLists.txt

@@ -66,7 +66,11 @@ fast_float_add_cpp_test(rcppfastfloat_test)
 fast_float_add_cpp_test(example_test)
 fast_float_add_cpp_test(example_comma_test)
 fast_float_add_cpp_test(basictest)
-option(FASTFLOAT_CONSTEXPR_TESTS "Require constexpr tests (build will fail if the compiler won't support it)" OFF)
+if(CMAKE_CXX_STANDARD GREATER_EQUAL 20)
+  option(FASTFLOAT_CONSTEXPR_TESTS "Require constexpr tests (build will fail if the compiler won't support it)" ON)
+else()
+  option(FASTFLOAT_CONSTEXPR_TESTS "Require constexpr tests (build will fail if the compiler won't support it)" OFF)
+endif()
 if (FASTFLOAT_CONSTEXPR_TESTS)
   target_compile_features(basictest PRIVATE cxx_std_20)
   target_compile_definitions(basictest PRIVATE FASTFLOAT_CONSTEXPR_TESTS)
@@ -84,11 +88,14 @@ fast_float_add_cpp_test(fast_int)
 target_compile_features(fast_int PRIVATE cxx_std_17)
 fast_float_add_cpp_test(json_fmt)
 fast_float_add_cpp_test(fortran)
-
-option(FASTFLOAT_FIXEDWIDTH_TESTS "Require fixed width test for C++23 (build will fail if the compiler won't support it)" OFF)
+if(CMAKE_CXX_STANDARD GREATER_EQUAL 23)
+  option(FASTFLOAT_FIXEDWIDTH_TESTS "Require fixed width test for C++23 (build will fail if the compiler won't support it)" ON)
+else()
+  option(FASTFLOAT_FIXEDWIDTH_TESTS "Require fixed width test for C++23 (build will fail if the compiler won't support it)" OFF)
+endif()
 if (FASTFLOAT_FIXEDWIDTH_TESTS)
   fast_float_add_cpp_test(fixedwidthtest)
-  target_compile_features(fixedwidthtest PRIVATE cxx_std_23)
+  target_compile_features(fixedwidthtest PUBLIC cxx_std_23)
 endif()
 
 option(FASTFLOAT_EXHAUSTIVE "Exhaustive tests" OFF)

tests/fixedwidthtest.cpp

@@ -1,46 +1,58 @@
 #include <cstdlib>
 #include <iostream>
 #include <vector>
-#include <iomanip>
 #include <cstring>
 #include "fast_float/fast_float.h"
 #include <cstdint>
 #include <stdfloat>
 
-int main()
-{
+int main() {
   // Write some testcases for the parsing of floating point numbers in the float32_t type.
   // We use the from_chars function defined in this library.
-
+#if __STDCPP_FLOAT32_T__
   const std::vector<std::float32_t> float32_test_expected{123.456f, -78.9f, 0.0001f, 3.40282e+038f};
-  const std::vector<std::string> float32_test{"123.456", "-78.9", "0.0001", "3.40282e+038"};
+  const std::vector<std::string_view> float32_test{"123.456", "-78.9", "0.0001", "3.40282e+038"};
 
   for (std::size_t i = 0; i < float32_test.size(); ++i) {
     const auto& f = float32_test[i];
     std::float32_t result;
     auto answer = fast_float::from_chars(f.data(), f.data() + f.size(), result);
 
-    if (answer.ec != std::errc() || result != float32_test_expected[i]) {
-      std::cerr << "Test failed for input: " << std::quoted(f) << std::endl;
+    if (answer.ec != std::errc()) {
+      std::cerr << "Failed to parse: \"" << f << "\"" << std::endl;
+      return EXIT_FAILURE;
+    }
+    if(result != float32_test_expected[i]) {
+      std::cerr << "Test failed for input: \"" << f << "\" expected " << float32_test_expected[i] << " got " << result << std::endl;
       return EXIT_FAILURE;
     }
   }
+#else
+  std::cout << "No std::float32_t type available." << std::endl;
+#endif
 
+#if __STDCPP_FLOAT64_T__
   // Test cases for std::float64_t
   const std::vector<std::float64_t> float64_test_expected{1.23e4, -5.67e-8, 1.7976931348623157e+308, -1.7976931348623157e+308};
-  const std::vector<std::string> float64_test{"1.23e4", "-5.67e-8", "1.7976931348623157e+308", "-1.7976931348623157e+308"};
+  const std::vector<std::string_view> float64_test{"1.23e4", "-5.67e-8", "1.7976931348623157e+308", "-1.7976931348623157e+308"};
 
   for (std::size_t i = 0; i < float64_test.size(); ++i) {
     const auto& f = float64_test[i];
     std::float64_t result;
     auto answer = fast_float::from_chars(f.data(), f.data() + f.size(), result);
 
-    if (answer.ec != std::errc() || result != float64_test_expected[i]) {
-      std::cerr << "Test failed for input: " << std::quoted(f) << std::endl;
+    if (answer.ec != std::errc()) {
+      std::cerr << "Failed to parse: \"" << f << "\"" << std::endl;
+      return EXIT_FAILURE;
+    }
+    if(result != float32_test_expected[i]) {
+      std::cerr << "Test failed for input: \"" << f << "\" expected " << float32_test_expected[i] << " got " << result << std::endl;
       return EXIT_FAILURE;
     }
   }
-
+#else
+  std::cout << "No std::float64_t type available." << std::endl;
+#endif
   std::cout << "All tests passed successfully." << std::endl;
   return EXIT_SUCCESS;