Basic Use of Namespaces Sample

Description

A C++ namespace is used to group together a set of function, type, and data definitions. For example, in this code:

	namespace A {
		void f() {}
		int x = 100;
	}
there is a namespace A with two members f() and x. Members of the namespace can be referenced by names like A::f() or by saying using namespace A or using A::f. A namespace represents a logical grouping of related declarations.

A namespace may be split into several parts, for example by saying:

	namespace A {
		void f() {}
	}

	...

	namespace A {
		void g() {}
	}
which declares only one namespace, with two members f() and g().

Concept

The sample program defines a namespace, and shows how members of the namespace are distinguished from global functions and data. To access namespace members, their names are prefaced with A::.

Special Notes:

The C++ Standard Library makes heavy use of namespaces, for example to define the std namespace that groups together standard functions and types. You frequently see:

	using namespace std;
at the top of programs, which means that members of the standard library are to be made available to the program.

Supported
Supported
Supported