std::string formatting like sprintf

Question

I have to format std::string with sprintf and send it into file stream. How can I do this?

Answer 1

template
std::string string_format(const char* fmt, Args... args)
{
    size_t size = snprintf(nullptr, 0, fmt, args...);
    std::string buf;
    buf.reserve(size + 1);
    buf.resize(size);
    snprintf(&buf[0], size + 1, fmt, args...);
    return buf;
}

Using C99 snprintf and C++11