[news:comp.std.c++ added. -drt]

"Douglas A. Gwyn" wrote:
>
> David R Tribble wrote:
>> The question still stands, though: Are these ill-formed in C?
>> C++98 goes to the trouble of spelling this case out explicitly; C99
>> doesn't.
>
> There is nothing wrong with them in C99.  I don't know why C++98
> went out of its way to outlaw them.  (Presumably it has something
> to do with destructors, but I don't see a problem.)

Probably it was because C++ has an extra sticky notion of scope in a
controlled statement.  For example:

    if (c)
        int  i;      // [A] scope is within the if-stmt
    else if (c2)
        foo();       // [B] scope is within the if-stmt
    else
    {
        int  j;      // [C] scope is also within the if-stmt
    }

Another reason might be because declarations are allowed (see above),
which means (like you said) that constructor/destructor calls are
allowed within the scope of the controlling statement.  Since C99
does not allow declarations as controlled statements (making [A]
illegal), this is a non-issue in C99.

Or perhaps they simply decided that it made more sense to treat
compound-statements and simple-statements the same, so that [C]
does not create an extra scope.

-- David R. Tribble, david@tribble.com, http://david.tribble.com --

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