[Bug libstdc++/56170] Extension debug_allocator seems non-compliant w.r.t. rebind

[redi at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=56170

--- Comment #7 from Jonathan Wakely <redi at gcc dot gnu.org> 2013-02-02 13:30:09 UTC ---
I think that could be useful, although as I don't know how many people still
use the concept checks I'm inclined to say that adding static_assert checks in
C++11 mode is more useful and can give shorter plain English errors, i.e.

static_assert( __is_allocator_type<_Alloc>::value, "Template parameter 4 does
not meet allocator requirements" );

Or maybe:

static_assert( __assert_allocator_type<_Alloc>::value, "Template parameter 4
does not meet allocator requirements" );

where __assert_allocator_type contains its own static_asserts with more
fine-grained checks for various aspects of the requirements.