[boost] [config] BOOST_NO_CXX11_ALLOCATOR and template aliases

Subject: [boost] [config] BOOST_NO_CXX11_ALLOCATOR and template aliases
From: Peter Dimov (lists_at_[hidden])
Date: 2014-02-05 08:32:12

VC11 appears to not define BOOST_NO_CXX11_ALLOCATOR. However, as 
std::allocator_traits contains two template aliases, rebind_alloc and 
rebind_traits, and VC11 doesn't support template aliases, it has nonstandard 
definitions of these two.

This is obviously a problem for code that wants to use 
std::allocator_traits.

One way to fix that is for the user code to check 
BOOST_NO_CXX11_TEMPLATE_ALIASES and if so, refrain from using 
std::allocator_traits.

Another is to just not define BOOST_NO_CXX11_ALLOCATOR for VC11. (VC12 is 
conforming.)

I tend to be in favor of the second option, as the effect would essentially 
be the same.