C++的String.Format

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

std::string string_format(const std::string& fmt, ...) {
    std::ostringstream oss;
    va_list args;
    va_start(args, fmt);
    for (size_t i = 0; i < fmt.size(); ++i) {
        if (fmt[i] == '{') {
            ++i;
            if (i < fmt.size() && fmt[i] == '}') {
                oss << va_arg(args, int);
            } else {
                oss << '{';
            }
        } else if (fmt[i] == '}') {
            ++i;
            if (i < fmt.size() && fmt[i] == '{') {
                oss << '}';
            } else {
                oss << '}';
            }
        } else {
            oss<< fmt[i];
        }
    }
    va_end(args);
    return oss.str();
}

int main() {
    std::string result = string_format("Hello, {0}! Today is {1}.", "Alice", "Monday");
    std::cout<< result<< std::endl;
    return 0;
}