C++ 用__attribute__((deprecated(message)))管理废弃API

__attribute__((deprecated(message)))可用于管理废弃API函数或者变量，同时保留其兼容性

#include <iostream>

#define MY_DEPR(message) __attribute__((deprecated(message)))

MY_DEPR("Please use test_fun2() instead.")
int test_fun(){

    return 0;
}

int test_fun_2(){

    return 0;
}

MY_DEPR("Please use class B instead.")
class A{};
class B{};

int main(int argc, char**argv){
    test_fun();
    A a;
    return 0;
}

result（输出一些警告信息，并提示需要更换的API或者类型）:
deprecated.cpp:17:7: warning: attribute ignored in declaration of ‘class A’ [-Wattributes]
 class A{};
       ^
deprecated.cpp:17:7: note: attribute for ‘class A’ must follow the ‘class’ keyword
deprecated.cpp: In function ‘int main(int, char**)’:
deprecated.cpp:20:14: warning: ‘int test_fun()’ is deprecated: Please use test_fun2() instead. [-Wdeprecated-declarations]
     test_fun();
              ^
deprecated.cpp:6:5: note: declared here
 int test_fun(){

扩展：

// 在opencv中可以这样使用
#if defined __GNUC__
    #define __CV_GPU_DEPR_BEFORE__
    #define __CV_GPU_DEPR_AFTER__ __attribute__ ((deprecated))
#elif defined(__MSVC__) //|| defined(__CUDACC__)
    #pragma deprecated(DevMem2D_)
    #define __CV_GPU_DEPR_BEFORE__ __declspec(deprecated)
    #define __CV_GPU_DEPR_AFTER__
#else
    #define __CV_GPU_DEPR_BEFORE__
    #define __CV_GPU_DEPR_AFTER__
#endif