断言assert()与调试帮助

assert(expr);

#include<iostream>
#include<string>
// 去注释则禁用 assert()
//#define NDEBUG
#include<cassert>
using namespace std;
int main()
{
    string word;
    size_t the = 5;
    cin >> word;
    assert(word.size() > the);

    if (word.size() < the) {
        cerr << "Error :" << __FILE__
            << " : in function " << __func__
            << " at line " << __LINE__ << endl
            << "        Compiled on " << __DATE__
            << " at " << __TIME__ << endl
            << "        Word read was \"" << word
            << "\": Length too short " << endl;
    }

    return 0;
}

#include<iostream>
#include<string>
#include<cassert>
using namespace std;
#define NDEBUG
using namespace std;
int main()
{
    string word;
    size_t the = 5;
    cin >> word;
    assert(word.size() > the);

    if (word.size() < the) {
        cerr << "Error :" << __FILE__
            << " : in function " << __func__
            << " at line " << __LINE__ << endl
            << "        Compiled on " << __DATE__
            << " at " << __TIME__ << endl
            << "        Word read was \"" << word
            << "\": Length too short " << endl;
    }

    return 0;
}

// cassert standard header
// NOTE: no include guard
#include <yvals.h>
#include <assert.h>

//
// assert.h
//
//      Copyright (c) Microsoft Corporation. All rights reserved.
//
// Defines the assert macro and related functionality.
//
#if defined _VCRT_BUILD && !defined _ASSERT_OK
    #error assert.h not for CRT internal use
#endif

#include <corecrt.h>

_CRT_BEGIN_C_HEADER

#undef assert

#ifdef NDEBUG

    #define assert(expression) ((void)0)

#else

    _ACRTIMP void __cdecl _wassert(
        _In_z_ wchar_t const* _Message,
        _In_z_ wchar_t const* _File,
        _In_   unsigned       _Line
        );

    #define assert(expression) (void)(                                                       \
            (!!(expression)) ||                                                              \
            (_wassert(_CRT_WIDE(#expression), _CRT_WIDE(__FILE__), (unsigned)(__LINE__)), 0) \
        )

#endif

_CRT_END_C_HEADER

__FILE__    //存放文件名的字符串字面值
__LINE__    //存放当前行号的整型字面值
__TIME__    //存放文件编译时间的字符串字面值
__DATE__    //存放文件编译日期的字符串字面值