Support polymorphic_allocator in boost::unordered_map/set

[skhoroshavin@…]

Right now boost::unordered_map/set require rebind struct in allocator, which is absent in polymorphic_allocator. This makes it impossible to use polymorphic_allocator "as is" in unordered containers.

[anonymous]

For now, you might be able to get it work by defining BOOST_UNORDERED_USE_ALLOCATOR_TRAITS to 1. That will tell it to use std::allocator_traits.

[skhoroshavin@…]

Replying to anonymous:

For now, you might be able to get it work by defining BOOST_UNORDERED_USE_ALLOCATOR_TRAITS to 1. That will tell it to use std::allocator_traits.

Thanks for pointing, it solved the issue. However I think it would be much better if this was either documented or enabled by default for compilers supporting it.

[anonymous]

The "for now" was to suggest that this is a temporary workaround. I can't do anything at the moment because we're at the end of a release cycle.

[Daniel James]

Should be fixed in master, in this merge:

​https://github.com/boostorg/unordered/commit/8a0592a35d5987fd33b49f2c63838e82f4f63be6

[sergey.korytnik@…]

The same problem with boost::multi_index class. It expects Allocator::rebind struct.