std::pmr::monotonic_buffer_resource::do_is_equal (3) - Linux Manuals
virtual bool do_is_equal(const std::pmr::memory_resource& other) const noexcept; (since C++17)
Compare *this with other for identity - memory allocated using a monotonic_buffer_resource can only be deallocated using that same resource.
this == &other
The following behavior-changing defect reports were applied retroactively to previously published C++ standards.
DR Applied to Behavior as published Correct behavior
LWG_3000 C++17 unnecessary dynamic_cast was performed removed
do_is_equal compare for equality with another memory_resource