C++ Primer Plus, Fourth Edition

Members Common to All Containers

All containers define the types in Table G.1. In this table, X is a container type, such as vector<int>, and T is the type stored in the container, such as int.

Table G.1. Types Defined for All Containers

Type	Value
X::value_type	T, the element type
X::reference	Behaves like T &
X::const_reference	Behaves like const T &
X::iterator	Iterator type pointing to T, behaves like T *
X::const_iterator	Iterator type pointing to const T, behaves like const T *
X::difference_type	Signed integral type used to represent the distance from one iterator to another; for example, the difference between two pointers
X::size_type	Unsigned integral type size_type can represent size of data objects, number of elements, and subscripts ...