std::pmr::set_default_resource
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                    | Defined in header  <memory_resource> | ||
| std::pmr::memory_resource* set_default_resource(std::pmr::memory_resource* r); | (since C++17) | |
If r is not null, sets the default memory resource pointer to r; otherwise, sets the default memory resource pointer to std::pmr::new_delete_resource.
The default memory resource pointer is used by certain facilities when an explicit memory resource is not supplied. The initial default memory resource pointer is the return value of std::pmr::new_delete_resource.
This function is thread-safe. Every call to std::pmr::set_default_resource synchronizes with (see std::memory_order) the subsequent std::pmr::set_default_resource and std::pmr::get_default_resource calls.
[edit] Return value
Returns the previous value of the default memory resource pointer.
[edit] Exceptions
noexcept specification:  
noexcept
  [edit] See also
| (C++17) | gets the default std::pmr::memory_resource (function) | 
| (C++17) | returns a static program-wide std::pmr::memory_resource that uses the global operator new and operator delete to allocate and deallocate memory (function) | 


