features.hpp

// Copyright (c) 2024-2025 xlnt-community
//
// Permission is hereby granted, free of charge, to any person obtaining a copy
// of this software and associated documentation files (the "Software"), to deal
// in the Software without restriction, including without limitation the rights
// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
// copies of the Software, and to permit persons to whom the Software is
// furnished to do so, subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included in
// all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
// THE SOFTWARE
//
// @license: http://www.opensource.org/licenses/mit-license.php
// @author: see AUTHORS file

#pragma once

#include <xlnt/utils/environment.hpp>

// Header detection helper. Available beginning with C++17.
#ifdef __has_include
  #define XLNT_HAS_INCLUDE(HEADER_NAME) __has_include(HEADER_NAME)
#else
  #define XLNT_HAS_INCLUDE(HEADER_NAME) 0
#endif

// If available, allow using C++20 feature test macros for precise feature testing. Useful for compilers
// that partially implement certain features.
#if XLNT_HAS_INCLUDE(<version>)
  #include <version>
#endif

// If you get a division by zero error, you probably misspelled the feature name.
// Developer note: XLNT_DETAIL_FEATURE_##feature should be set to
//    1: if feature is supported
//    -1: if the feature is not supported
#define XLNT_HAS_FEATURE(feature) (1/XLNT_DETAIL_FEATURE_##feature == 1)

// Note: the first check ensures that a compiler partially implementing C++17 but implementing std::to_chars
// would be detected correctly, as long as the C++20 feature test macros are implemented. The second check
// ensures that a fully implemented C++17 compiler would be detected as well.
#if defined(__cpp_lib_to_chars) || XLNT_HAS_CPP_VERSION(XLNT_CPP_17)
  #define XLNT_DETAIL_FEATURE_TO_CHARS 1
#else
  #define XLNT_DETAIL_FEATURE_TO_CHARS -1
#endif

#if defined(__cpp_lib_string_view) || XLNT_HAS_CPP_VERSION(XLNT_CPP_17)
  #define XLNT_DETAIL_FEATURE_STRING_VIEW 1
#else
  #define XLNT_DETAIL_FEATURE_STRING_VIEW -1
#endif

#if defined(__cpp_lib_filesystem) || XLNT_HAS_CPP_VERSION(XLNT_CPP_17)
  #define XLNT_DETAIL_FEATURE_FILESYSTEM 1
#else
  #define XLNT_DETAIL_FEATURE_FILESYSTEM -1
#endif

#if XLNT_HAS_FEATURE(STRING_VIEW) && defined(__cpp_lib_char8_t)
  #define XLNT_DETAIL_FEATURE_U8_STRING_VIEW 1
#else
  #define XLNT_DETAIL_FEATURE_U8_STRING_VIEW -1
#endif