std::pmr::memory_resource::do_is_equal
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                    < cpp | memory | memory resource
                    
                                                            
                    | virtual bool is_equal(const std::pmr::memory_resource& other) const = 0; | (since C++17) | |
Compares *this for equality with other.
Two memory_resources compare equal if and only if memory allocated from one memory_resource can be deallocated from the other and vice versa.
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.
Exceptions
noexcept specification:  
noexcept
  See also
| compare for equality with another memory_resource(public member function) |