std::pmr::null_memory_resource
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                    | Defined in header  <memory_resource> | ||
| std::pmr::memory_resource* null_memory_resource(); | (since C++17) | |
Returns a pointer to a memory_resource that doesn't perform any allocation.
[edit] Return value
Returns a pointer p to a static storage duration object of a type derived from std::pmr::memory_resource, with the following properties:
-  its allocate()function always throws std::bad_alloc;
-  its deallocate()function has no effect;
-  for any memory_resourcer,p->is_equal(r)returns&r == p.
The same value is returned every time this function is called.
[edit] Exceptions
noexcept specification:  
noexcept
  

