【 genius_platform software platform development 】 : seventy-six vs the preprocessor definitions written cow force!!!!!!!!!!(in the other groups conding personnel told so cow force configuration to can

1.问题概述

• Today, the small partners in the group are debugging the algorithm interface,Always crashes at the algorithm interface,发现vs提示信息为vector too long…The result algorithm guy told to set the precompiler definition _HAS_ITERATOR_DEBUGGING=0Cancel the macro definition.我擦,这是什么骚操作,It's okay to play like this,It looks like there is a problem,As a result, the definition of the macro cannot be cancelled in order to prove that this is the case,It is hereby verified;
  

2. main.cpp源代码（vs2017环境,其他vs环境都可以）：

#ifdef _HAS_ITERATOR_DEBUGGING
#define x_1 1
#pragma message ("#define x_1 1")
#endif

#ifdef _HAS_ITERATOR_DEBUGGING
#define y_1 1
#pragma message ("#define y_1 1")
#endif

#include <iostream>

int main()
{
    
    //int x = 0;
    #ifdef _HAS_ITERATOR_DEBUGGING
    {
    
        printf("#ifdef _HAS_ITERATOR_DEBUGGING\n");
        printf("x_z = %d\n", _HAS_ITERATOR_DEBUGGING);
        printf("x_1 = %d\n", x_1);
        printf("y_1 = %d\n", y_1);
    }
    #endif

    if (_HAS_ITERATOR_DEBUGGING == 0)
    {
    
        printf("if (_HAS_ITERATOR_DEBUGGING == 0)\n");
        printf("x_z = %d\n", _HAS_ITERATOR_DEBUGGING);
        printf("x_1 = %d\n", x_1);
        printf("y_1 = %d\n", y_1);
    }

    if (_HAS_ITERATOR_DEBUGGING == 1)
    {
    
        printf("if (_HAS_ITERATOR_DEBUGGING == 1)\n");
        printf("x_z = %d\n", _HAS_ITERATOR_DEBUGGING);
        printf("x_1 = %d\n", x_1);
        printf("y_1 = %d\n", y_1);
    }

    if (_HAS_ITERATOR_DEBUGGING == 2)
    {
    
        printf("if (_HAS_ITERATOR_DEBUGGING == 2)\n");
        printf("x_z = %d\n", _HAS_ITERATOR_DEBUGGING);
        printf("x_1 = %d\n", x_1);
        printf("y_1 = %d\n", y_1);
    }

   // printf("%d\n", vtkBooleanMacro(x,=,1));

    std::cout << "Hello World!\n";
    getchar();
}

3. The preprocessor is defined as_HAS_ITERATOR_DEBUGGING=0

3.1 See recompilelog

• This macro is predefined by the editor_HAS_ITERATOR_DEBUGGING 为 0,但是该 _HAS_ITERATOR_DEBUGGING still belong to the predefined state;
  

3.2 查看运行结果

• #ifdef _HAS_ITERATOR_DEBUGGING Judgments are predefined,或者使用if(_HAS_ITERATOR_DEBUGGING == 0/1)This kind of shit is rare,Can't get it to cancel_HAS_ITERATOR_DEBUGGING 的定义
  

4. The preprocessor is defined as_HAS_ITERATOR_DEBUGGING=1

4.1 See recompilelog

• This macro is predefined by the editor_HAS_ITERATOR_DEBUGGING 为 1,但是该 _HAS_ITERATOR_DEBUGGING still belong to the predefined state;
  

4.1 查看运行结果

5. The preprocessor is defined as_HAS_ITERATOR_DEBUGGING=2

5.1 See recompilelog

• 编译阶段直接报错,如图;
  
  

6. 总结

• As long as it is defined in the preprocessor interface_HAS_ITERATOR_DEBUGGING宏,That is, the editor will define the macro during the editing phase.This macro will generally not be executed again=赋值操作（Must be a cognitive error,I want to cancel the definition of this macro）;
• If you really want to play tricks、A mess of abnormal settings,Then it can only be set to 0/1（This is rarely used）;And it can only be used in the programif(_HAS_ITERATOR_DEBUGGING == xxxx)Judgment in other forms,#ifdef _HAS_ITERATOR_DEBUGGING always valid,Predefined macros;
• I want to cancel the setting of a macro,配置成_HAS_ITERATOR_DEBUGGING=0It does not work to cancel the macro definition;Really want to cancel or remove the configuration of this macro;