Standard C++ library overview

All C++ library entities are declared or defined in one or more standard headers. To make use of a library entity in a program, write an include directive that names the relevant standard header. The Standard C++ Library consists of 50 required headers. This implementation also includes two additional headers, and , that are not required by the C++ Standard, for a total of 52 headers. These 52 C++ library headers (with the additional 18 Standard C headers) constitute a hosted implementation of the C++ library.

A freestanding implementation of the C++ library provides only a subset of these headers:

	(declaring at least the functions abort, atexit, and exit)

The C++ library headers have two broader subdivisions: