Re: Cast as you can (VC++ 6.0)

[James W. W. <ja...@wr...>]

Jose' Cruanyes <cru...@ce...> wrote:

>I'm trying to compile Quesa with VC++ 6.0, and an issue has risen
>
>the cast on l-values are not allowed in MS VC++
>
>this expression is illegal in C++ (according to MS)
>
>myStruct * myStructPtr;
>
>((char*) myStructPtr)) += sizeOfMyStruct
>
>error C2106 left operand must be l-value...
>
>there are 44 of them in quesa
>
>several other changes had been made, but this is serious
>do you know a way to avoid it?


It looks as though MS may be right.  The 1998 C++ standard says: "The 
result of the expression (T) cast-expression is of type T. The result 
is an lvalue if T is a reference type, otherwise the result is an 
rvalue."  However, I don't see any way to get CodeWarrior to even 
give me a warning about this.

Would it make sense to say this?

((char*&) myStructPtr)) += sizeOfMyStruct;

That compiles in CodeWarrior, and the reference may make it legal, 
but it looks tricky.
-- 
   James W. Walker, ScriptPerfection Enterprises, Inc.
   <http://www.write-brain.com/>