Function string_vprintf

src/butil/string_printf.cpp:146–153

};

int string_vprintf(std::string* output, const char* format, va_list args) {
    output->clear();
    const int rc = string_printf_impl(*output, format, args);
    if (rc != 0) {
        output->clear();
    }
    return rc;
};

}  // namespace butil