nanxing_stl/lib/tests/print_result.h

#ifndef NANXING_TEST_PRINT_
#define NANXING_TEST_PRINT_
#include<fstream>
#include<string>
#include<iostream>
#include<type_traits>
namespace nanxing_test{
    template<typename K>
    using void_t=void;

    template<typename K,typename V=void>
    struct ofstream_admit:std::false_type{};

    template<typename K>
    struct ofstream_admit<K,void_t<decltype(std::declval<std::ofstream&>()<<std::declval<K>())>>:std::true_type{};

    template<typename T>
    static void inseat_result_to_txt(T result)
    {
        static_assert(ofstream_admit<T>::value,"The type of T cannot print by ofstream");
        std::ofstream output("../../test_result.txt",std::ios_base::app);
        if(!output.is_open())
        {
            std::cerr << "Failed to open the file." << std::endl;
        }
        output<<result<<std::endl;
        output.close();
    }
}

#endif