与Rust的include_str等效的C++宏

#include <iostream>
#include <sstream>
#include <string>

#define INCLUDE_STR(filename) \
    ([]() -> std::string { \
        std::stringstream ss; \
        std::ifstream file(filename); \
        if (!file.is_open()) { \
            throw std::runtime_error("Could not open file"); \
        } \
        ss << file.rdbuf(); \
        return ss.str(); \
    })()

int main() {
    try {
        std::string content = INCLUDE_STR("example.txt");
        std::cout << content << std::endl;
    } catch (const std::exception& e) {
        std::cerr << e.what() << std::endl;
    }
    return 0;
}

#include <boost/preprocessor/stringize.hpp>
#include <iostream>

#define INCLUDE_STR(filename) BOOST_PP_STRINGIZE(filename)

int main() {
    std::string content = INCLUDE_STR(example.txt);
    std::cout << content << std::endl;
    return 0;
}

#include <iostream>
#include <string_view>
#include <embed>

int main() {
    std::string_view content = std::embed("example.txt");
    std::cout << content << std::endl;
    return 0;
}