std::experimental::pmr::memory_resource::do_is_equal
Min standard notice:
Compares *this for equality with other.
# Declarations
virtual bool is_equal( const memory_resource& other ) const noexcept = 0;
(library fundamentals TS)
# Notes
The most-derived type of other may not match the most derived type of *this. A derived class implementation therefore must typically check whether the most derived types of *this and other match using dynamic_cast, and immediately return false if the cast fails.