d安全句柄

原文

module safehandle;

import core.sys.windows.windows;
import std.typecons;

struct Unique( T, alias DTOR )
{
    ...

    ~this()
    {
        if (_p !is null)
        {
            DTOR( _p );
            destroy(_p);
            _p = null;
        }
    }

   ...
}

alias SafeHandle = Unique!(void,CloseHandle);
//使用:

SafeHandle open_keyboard_device2( ... )
{
    ...

    SafeHandle dev_handle =
        CreateFileW( ... );

    ...

    return dev_handle;
}
void main()
{
    ...

    auto dev = open_keyboard_device2( ... );
    process_device( dev );

    ...

    // auto-close handle
}

//未来:

alias SafeHandle        = Unique!(void,CloseHandle)
alias Safe_SDL_Window   = Unique!(SDL_Window,SDL_DestroyWindow)
alias Safe_SDL_Surface  = Unique!(SDL_Surface,SDL_FreeSurface)
alias Safe_SDL_Texture  = Unique!(SDL_Texture,SDL_DestroyTexture)
alias Safe_SDL_Renderer = Unique!(SDL_Renderer,SDL_DestroyRenderer)