Add the hset container.
Add the _args alias to args<>.
Fix underlining of %Type column in concept documentation.
Add the optimization mechanism.
Specialize has_optimization in vector.
Add an optimized version of foldl.
Add eager *_t aliases as in C++14.
Use identity in always' implementation.
Use *_t aliases to reduce syntactic overhead.
new_ takes a Sequence instead of an argument pack.
Fix reference to Container instead of template param in associative_container.
Add AssociativeContainer to minimal_requirements.