#define CURSOR(top,bottom) (((top)<<8)|(bottom))

#define mul(x1,x2) (x1*x2)

#define WIDTH 8

#define LENGTH (WIDTH+10)

/**

 *

 * check is c++ compiler

 */

#if !defined(__cplusplus)

    #error c++ compiler requires

#endif

#if defined(CLANG)//if defined CLANG use below code

   void compiler()

   {

       std::cout<<"use clang"<<std::endl;

   }

#elif defined(GUNC)

    void compiler()

    {

        std::cout<<"use gunc++"<<std::endl;

    }

#else

    void compiler()

    {

        std::cout<<"unknown compiler"<<std::endl;

    }

#endif

#define DLEVEL 5

#if DLEVEL > 5

    #define SIGNAL 1

    #if STACKUSE == 1

        #define STACK 200

    #else

        #define STACK 100

    #endif

#else

    #define SIGNAL 0

    #if STACKUSE == 1

        #define LEVEL 1

        #define STACK 100

    #else

        #define STACK 50

    #endif

#endif

#if LEVEL == 0

    #define STACK 0

#elif DELEVEL == 1

    #define STACK 100

#elif DLEVEL > 5

    display(debugptr);

#else

    #define STACK 200

#endif

/* EXAMPLE.H - Example header file*/

#if !defined(EXAMPLE_H)

    #define EXAMPLE_H

class Example

{

};

#endif

/**

 *

 *Visual Studio 2017 version 15.3 and later,检查库头文件是否包含

 */

#

#ifdef _has_include

# if _has_include(<filesystem>)

#   inculde <filesystem>

#   define have_filesystem

# elif _has_include(<experimental/filesystem>)

#   include <experimental/filesystem>

#   define have_filesystem

#   define experimental_filesystem

# else

#   define have_filesystem

# endif

#endif

#ifndef test

#define final

#endif

//has no effect

#

//stringizing 操作符转换宏指令参数成字符串字面量.

//比如下面这句 "This: \"  prints an escaped double quote"

#define stringer(x) printf(#x "\n")

#define F int

#define B def

#define FB(arg) #arg

#define FB1(arg) FB(arg)