在 linux 和 windows 中使用 #define 宏 Function 的最佳方法是什么？

Question

WindowsAPI functions currently used in the following examples for Linux

I want to use it as one definition depending on the platform.

example.

#ifdef _WIN32
            ::CopyMemory(dest, readBuffer_ + fileOffset - readBufferOffset_, size);
#elif __linux__
            memcpy(dest, readBuffer_ + fileOffset - readBufferOffset_, size);
#endif

If there are a lot of processing like the above in the code, the readability is reduced. So I want to use something like this, but I'm not sure what is a good way to do it.

#ifdef _WIN32
  #define MEM_COPY CopyMemory
  #define SET_FILE_POINTER SetFilePointer
  #define READ_FILE ReadFile
#elif __linux
  #define MEM_COPY memcpy
  #define SET_FILE_POINTER lseek // parameter sequence not equal to SetFilePointer
  #define READ_FILE read
#endif


int main()
{
  // i wanna use one function (READ_FILE) both in linux and Windows
  READ_FILE(dest, readBuffer_ + fileOffset - readBufferOffset_, size);
}

I have an additional question.

Windows has many safety functions.

ex) fopen_s memcpy_s

in linux I've seen memcpy used frequently. How do you usually judge a standard that guarantees safety? (Is it ok to just use it normally? I have the linux manual manpage, I saw the note contents.)

Answer 1

I would use an abstraction layer for that in a namespace:

namespace OperatingSystemFunctions
{
    static void CopyMemory(arguments)
    {
#ifdef _WIN32
            ::CopyMemory(dest, readBuffer_ + fileOffset - readBufferOffset_, size);
#elif __linux__
            memcpy(dest, readBuffer_ + fileOffset - readBufferOffset_, size);
#endif    
    }
}



int main()
{
    MyMemoryCopy::CopyMemory(...);
}

Of course the arguments needs to match for that approach.