[Bug c++/43453] Initialization of char array with string literal fails in mem-initializer

["schaub.johannes at googlemail dot com" <gcc-bugzilla@gcc.gnu.org>]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=43453

--- Comment #4 from Johannes Schaub <schaub.johannes at googlemail dot com> 2011-05-14 16:18:58 UTC ---
(In reply to comment #3)
> (In reply to comment #2)
> > (In reply to comment #1)
> > > (In reply to comment #0)
> > > > Fails to compile, but should work:
> > > > 
> > > > struct A { 
> > > >   char x[4]; 
> > > >   A():x("bug") { } 
> > > > };
> > > > 
> > > > Error i get is:
> > > > 
> > > > "main.cpp:3: error: array used as initializer"
> > > > 
> > > 
> > > Why do you think it should work?  
> > > For example, the following equivalent code is invalid as well:
> > > 
> > > char x [4] ("bug");
> > > 
> > 
> > This code is equivalent and is valid. At least, I don't see the Standard
> > forbidding it. GCC is the only compiler I tested (comeau/edg, clang) that
> > rejects it.
> 
> I'm not actually sure anymore about the validity of this code. One can make a
> point about the initializer not being a mere string literal.
> 
> At least the draft n3126 makes a difference of this, in that an initializer
> like "({a, b, c})" is not regarded as a braced-init-list, but rather as a
> parenthesized expression-list where the initializer list is handed as one
> argument. So I'm unsure whether an initializer like `("foo")` should be
> regarded as a string literal or not.
> 
> I think I will send an issue report about this.

Subsequent discussion with Jason showed that this is covered by 8.5p13:

   The form of initialization (using parentheses or =) is generally 
   insignificant, but does matter when the initializer or the entity 
   being initialized has a class type;

As this is an array, the text in the Standard in general has to be interpreted
that a "=" or a "(..)" initializer are equivalent, unless otherwise stated. 

So this is indeed a GCC bug (both that it rejects the member initialization and
the parenthesized non-member initialization).