C++ In a Nutshell

Overview of the Standard Library

The standard library has 51 headers, each containing a set of macro, function, type, and object declarations. A header is sometimes called a header file, but that phrase is misleading. An implementation does not need to implement headers as external files, although it is often simplest to think of a header as a file that contains macro, type, and function declarations.

Almost all the names declared in the standard library are in the std namespace. Macros, of course, are not in any namespace, so it is important that you know which names are macros and which are not. The detailed descriptions in Chapter 13 tell you this information. The only other names that are outside the std namespace are the global operator new and operator delete functions, declared in the <new> header.

To use the standard library, you must #include the desired header or headers. Some implementations #include headers within other headers (e.g., <set> might #include <iterator>). The headers that a vendor includes within a header vary from one implementation to another, so code that compiles successfully with one vendor’s environment might not compile in a different environment. The solution is to get in the habit of including all the headers you need.

Warning

If you see headers of the form <iostream.h>, the program was probably written in the days before the C++ standard. It might ...