[mem.res.syn]

# 20 Memory management library [[mem]](./#mem)

## 20.5 Memory resources [[mem.res]](mem.res#syn)

### 20.5.1 Header <memory_resource> synopsis [mem.res.syn]

[ð](#header:%3cmemory_resource%3e)

namespace std::pmr {// [[mem.res.class]](mem.res.class "20.5.2 Class memory_­resource"), class memory_resourceclass memory_resource; bool operator==(const memory_resource& a, const memory_resource& b) noexcept; // [[mem.poly.allocator.class]](mem.poly.allocator.class "20.5.3 Class template polymorphic_­allocator"), class template polymorphic_allocatortemplate<class Tp = byte> class polymorphic_allocator; template<class T1, class T2>bool operator==(const polymorphic_allocator<T1>& a, const polymorphic_allocator<T2>& b) noexcept; // [[mem.res.global]](mem.res.global "20.5.4 Access to program-wide memory_­resource objects"), global memory resources memory_resource* new_delete_resource() noexcept;
 memory_resource* null_memory_resource() noexcept;
 memory_resource* set_default_resource(memory_resource* r) noexcept;
 memory_resource* get_default_resource() noexcept; // [[mem.res.pool]](mem.res.pool "20.5.5 Pool resource classes"), pool resource classesstruct pool_options; class synchronized_pool_resource; class unsynchronized_pool_resource; class monotonic_buffer_resource;}
