[cfe-commits] r56060 - /cfe/trunk/lib/Parse/ParseStmt.cpp

[Argiris Kirtzidis]

I think this is more explicit:

      // C++ 3.3.2p4:
      // Names declared in the for-init-statement, and in the condition 
of if,
      // while, for, and switch statements are local to the if, while, 
for, or
      // switch statement (including the controlled statement).

Should I replace the "C++ 6.4p3" quote, with the above one ?

-Argiris

Neil Booth wrote:
> Argiris Kirtzidis wrote:-
>
>   
>> +  //
>> +  // C++ 6.4p3:
>> +  // A name introduced by a declaration in a condition is in scope from its
>> +  // point of declaration until the end of the substatements controlled by the
>> +  // condition.
>>     
>
> I've read and reread the parts of the C++ standard, and I've just ended
> up confused.
>
> However I'm finding it hard to read this as saying a new scope is
> created and entered.
>
> For example, 
>
> int a, b;
>
> b is "in scope" from the character 'b' but you don't enter a new scope
> when you see the 'b'.
>
> In comparison C99 is very explicit that a whole new scope is created,
> as is C++ for the controlled statements.  So I don't see it for the
> outer statement in C++.
>
> This matters with, for example,
>
> void f(void)
> {
>   int x;
>
>   if (int x = 1)
>   {
>   }
> }
>
> where I read the C++ standard as requiring a redefinition of x
> error.
>
> Neil.
>
>