• Log in

namespace std::pmr {
 // class memory_resource
 class memory_resource;
 
 bool operator==(const memory_resource& a, const memory_resource& b) noexcept;
 
 // class template polymorphic_allocator
 template<class Tp> class polymorphic_allocator;
 
 template<class T1, class T2>
 bool operator==(const polymorphic_allocator<T1>& a,
 const polymorphic_allocator<T2>& b) noexcept;
 
 // 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;
 
 // pool resource classes
 struct pool_options;
 class synchronized_pool_resource;
 class unsynchronized_pool_resource;
 class monotonic_buffer_resource;
}

namespace std::pmr {
 class memory_resource {
 static constexpr size_t max_align = alignof(max_align_t); // exposition only
 
 public:
 memory_resource() = default;
 memory_resource(const memory_resource&) = default;
 virtual ~memory_resource();
 
 memory_resource& operator=(const memory_resource&) = default;
 
 void* allocate(size_t bytes, size_t alignment = max_align);
 void deallocate(void* p, size_t bytes, size_t alignment = max_align);
 
 bool is_equal(const memory_resource& other) const noexcept;
 
 private:
 virtual void* do_allocate(size_t bytes, size_t alignment) = 0;
 virtual void do_deallocate(void* p, size_t bytes, size_t alignment) = 0;
 
 virtual bool do_is_equal(const memory_resource& other) const noexcept = 0;
 };
}

namespace std::pmr {
 template<class Tp = byte> class polymorphic_allocator {
 memory_resource* memory_rsrc; // exposition only
 
 public:
 using value_type = Tp;
 
 // constructors
 polymorphic_allocator() noexcept;
 polymorphic_allocator(memory_resource* r);
 
 polymorphic_allocator(const polymorphic_allocator& other) = default;
 
 template<class U>
 polymorphic_allocator(const polymorphic_allocator<U>& other) noexcept;
 
 polymorphic_allocator& operator=(const polymorphic_allocator&) = delete;
 
 // member functions
 Tp* allocate(size_t n);
 void deallocate(Tp* p, size_t n);
 
 void* allocate_bytes(size_t nbytes, size_t alignment = alignof(max_align_t));
 void deallocate_bytes(void* p, size_t nbytes, size_t alignment = alignof(max_align_t));
 template<class T> T* allocate_object(size_t n = 1);
 template<class T> void deallocate_object(T* p, size_t n = 1);
 template<class T, class... CtorArgs>
 T* new_object(CtorArgs&&... ctor_args);
 template<class T> void delete_object(T* p);
 
 template<class T, class... Args>
 void construct(T* p, Args&&... args);
 
 template<class T>
 void destroy(T* p); // deprecated
 
 polymorphic_allocator select_on_container_copy_construction() const;
 
 memory_resource* resource() const;
 };
}

namespace std::pmr {
 struct pool_options {
 size_t max_blocks_per_chunk = 0;
 size_t largest_required_pool_block = 0;
 };
}

namespace std::pmr {
 class synchronized_pool_resource : public memory_resource {
 public:
 synchronized_pool_resource(const pool_options& opts, memory_resource* upstream);
 
 synchronized_pool_resource()
 : synchronized_pool_resource(pool_options(), get_default_resource()) {}
 explicit synchronized_pool_resource(memory_resource* upstream)
 : synchronized_pool_resource(pool_options(), upstream) {}
 explicit synchronized_pool_resource(const pool_options& opts)
 : synchronized_pool_resource(opts, get_default_resource()) {}
 
 synchronized_pool_resource(const synchronized_pool_resource&) = delete;
 virtual ~synchronized_pool_resource();
 
 synchronized_pool_resource& operator=(const synchronized_pool_resource&) = delete;
 
 void release();
 memory_resource* upstream_resource() const;
 pool_options options() const;
 
 protected:
 void* do_allocate(size_t bytes, size_t alignment) override;
 void do_deallocate(void* p, size_t bytes, size_t alignment) override;
 
 bool do_is_equal(const memory_resource& other) const noexcept override;
 };
}

namespace std::pmr {
 class unsynchronized_pool_resource : public memory_resource {
 public:
 unsynchronized_pool_resource(const pool_options& opts, memory_resource* upstream);
 
 unsynchronized_pool_resource()
 : unsynchronized_pool_resource(pool_options(), get_default_resource()) {}
 explicit unsynchronized_pool_resource(memory_resource* upstream)
 : unsynchronized_pool_resource(pool_options(), upstream) {}
 explicit unsynchronized_pool_resource(const pool_options& opts)
 : unsynchronized_pool_resource(opts, get_default_resource()) {}
 
 unsynchronized_pool_resource(const unsynchronized_pool_resource&) = delete;
 virtual ~unsynchronized_pool_resource();
 
 unsynchronized_pool_resource& operator=(const unsynchronized_pool_resource&) = delete;
 
 void release();
 memory_resource* upstream_resource() const;
 pool_options options() const;
 
 protected:
 void* do_allocate(size_t bytes, size_t alignment) override;
 void do_deallocate(void* p, size_t bytes, size_t alignment) override;
 
 bool do_is_equal(const memory_resource& other) const noexcept override;
 };
}

namespace std::pmr {
 class monotonic_buffer_resource : public memory_resource {
 memory_resource* upstream_rsrc; // exposition only
 void* current_buffer; // exposition only
 size_t next_buffer_size; // exposition only
 
 public:
 explicit monotonic_buffer_resource(memory_resource* upstream);
 monotonic_buffer_resource(size_t initial_size, memory_resource* upstream);
 monotonic_buffer_resource(void* buffer, size_t buffer_size, memory_resource* upstream);
 
 monotonic_buffer_resource()
 : monotonic_buffer_resource(get_default_resource()) {}
 explicit monotonic_buffer_resource(size_t initial_size)
 : monotonic_buffer_resource(initial_size, get_default_resource()) {}
 monotonic_buffer_resource(void* buffer, size_t buffer_size)
 : monotonic_buffer_resource(buffer, buffer_size, get_default_resource()) {}
 
 monotonic_buffer_resource(const monotonic_buffer_resource&) = delete;
 
 virtual ~monotonic_buffer_resource();
 
 monotonic_buffer_resource& operator=(const monotonic_buffer_resource&) = delete;
 
 void release();
 memory_resource* upstream_resource() const;
 
 protected:
 void* do_allocate(size_t bytes, size_t alignment) override;
 void do_deallocate(void* p, size_t bytes, size_t alignment) override;
 
 bool do_is_equal(const memory_resource& other) const noexcept override;
 };
}