C++11 implementations of standard components added in later C++ standards.
C++
11
Function object wrappers for deferred calls or callbacks.
C++
11
Open-methods are free-standing functions that work like virtual functions: they select the best overrider from a set, depending on the dynamic type of their arguments. This makes it possible to add polymorphic operations to existing classes, without modifying them. They make patterns like Visitor unnecessary.
C++
17
A deterministic failure handling library partially simulating lightweight exceptions.
C++
14
Boost.Parameter Library - Write functions that accept arguments by name.
C++
03