在C++中创建和使用跨平台结构

#include<boost/preprocessor/arithmetic/add.hpp>
#include<boost/preprocessor/control/if.hpp>
#include<boost/preprocessor/repetition/repeat.hpp>

#define PLATFORM_WINDOWS 1
#define PLATFORM_LINUX 2
#define PLATFORM_MACOS 3

#if defined(_WIN32)
#define CURRENT_PLATFORM PLATFORM_WINDOWS
#elif defined(__linux__)
#define CURRENT_PLATFORM PLATFORM_LINUX
#elif defined(__APPLE__)
#define CURRENT_PLATFORM PLATFORM_MACOS
#else
#error "Unknown platform"
#endif

#define PLATFORM_CASE(n, data, elem) \
    BOOST_PP_IF(BOOST_PP_EQUAL(n, CURRENT_PLATFORM), elem, )

#define PLATFORM_SWITCH(func_name, func_default, ...) \
    BOOST_PP_REPEAT(BOOST_PP_ADD(3, BOOST_PP_VARIADIC_SIZE(__VA_ARGS__)), PLATFORM_CASE, func_name##_impl(__VA_ARGS__)) \
    func_default()

#define PLATFORM_CASE_IMPL(func_name, platform, ...) \
    void func_name##_impl(platform, ##__VA_ARGS__)

// 定义跨平台结构
PLATFORM_CASE_IMPL(my_function, PLATFORM_WINDOWS) {
    // Windows平台的实现
}

PLATFORM_CASE_IMPL(my_function, PLATFORM_LINUX) {
    // Linux平台的实现
}

PLATFORM_CASE_IMPL(my_function, PLATFORM_MACOS) {
    // macOS平台的实现
}

// 使用跨平台结构
int main() {
    PLATFORM_SWITCH(my_function, default_function);
    return 0;
}