🚀 go-pugleaf

"Ed Mulroy [TeamB]" <dont_email_me@bitbuc.ket> wrote:

>Casting an lvalue may be uncommon but I do not think it is a non-standard
>extension.  Except for the case of GetProcAddress I think it is usually
>uglier and more difficult to understand than other ways of doing things so
>is best avoided.

To quote a footnote from the current C standard:

   85) A cast does not yield an lvalue.

And since assignment requires an lvalue as its target, this rather
implies that the cast-on-the-left method isn't actually legal.

>I think there must have been some other reason that you had to change your
>GetProcAdddress calls when using VC.  Casting to FARPROC on the left is not
>uncommon in MS code.  If I remember correctly, I first saw it in use in OS/2
>code when using an MS compiler.

I suspect that it's a bug in early compilers that got left in because
it's too useful for such code.

I actually use a template:

  template<typename FuncType> vool
  WireupFunction(HINSTANCE Inst, FuncType& FnPtr, char const* FnName)
  {
    FnPtr = reinterpret_cast<FuncType>(GetProcAddress(Inst, FnName));
    return (FnPtr != 0);
  }

  WireupFunction(m_Inst, ClearPrintString, "ClearPrintString");

Once the template exists, it's actually less typing.

Alan Bellingham
-- 
ACCU Conference 2004 - http://https://www.accu.org/conference/