std::pmr::unsynchronized_pool_resource::upstream_resource
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                    < cpp | memory | unsynchronized pool resource
                    
                                                            
                    | std::pmr::memory_resource* upstream_resource() const; | (since C++17) | |
Returns a pointer to the upstream memory resource. This is the same value as the upstream argument passed to the constructor of this object.
See also
| Constructs a unsynchronized_pool_resource(public member function) |