26 Containers library [containers]

26.2 Container requirements [container.requirements]

26.2.4 Node handles [container.node]

26.2.4.4 node_­handle observers [container.node.observers]

value_type& value() const;

Requires: empty() == false.

Returns: A reference to the value_­type subobject in the container_­node_­type object pointed to by ptr_­.

Throws: Nothing.

key_type& key() const;

Requires: empty() == false.

Returns: A non-const reference to the key_­type member of the value_­type subobject in the container_­node_­type object pointed to by ptr_­.

Throws: Nothing.

Remarks: Modifying the key through the returned reference is permitted.

mapped_type& mapped() const;

Requires: empty() == false.

Returns: A reference to the mapped_­type member of the value_­type subobject in the container_­node_­type object pointed to by ptr_­.

Throws: Nothing.

allocator_type get_allocator() const;

Requires: empty() == false.

Returns: *alloc_­.

Throws: Nothing.

explicit operator bool() const noexcept;

Returns: ptr_­ != nullptr.

bool empty() const noexcept;

Returns: ptr_­ == nullptr.