Function string_vappendf

src/butil/string_printf.cpp:129–136

}

int string_vappendf(std::string* output, const char* format, va_list args) {
    const size_t old_size = output->size();
    const int rc = string_printf_impl(*output, format, args);
    if (rc != 0) {
        output->resize(old_size);
    }
    return rc;
}

int string_printf(std::string* output, const char* format, ...) {
    va_list ap;