Standard Template Library Programmer's Guide

must be X::key_type.
X::value_compare	The type of a Strict Weak Ordering used to compare values. Its argument type must be X::value_type, and it compares two objects of value_type by passing the keys associated with those objects to a function object of type key_compare.

Notation

X A type that is a model of Sorted Associative Container

a Object of type X

t Object of type X::value_type

k Object of type X::key_type

p, q Object of type X::iterator

c Object of type X::key_compare

Valid expressions

In addition to the expressions defined in Associative Container and Reversible Container, the following expressions must be valid.

Name	Expression	Return type
Default constructor	X() X a;
Constructor with compare	X(c) X a(c);
Key comparison	a.key_comp()	X::key_compare
Value comparison	a::value_compare()	X::value_compare
Lower bound	a.lower_bound(k)	iterator if a is mutable, otherwise const_iterator.
Upper bound	a.upper_bound(k)	iterator if a is mutable, otherwise const_iterator.
Equal range	a.equal_range(k)	pair<iterator, iterator> if a is mutable, otherwise pair<const_iterator, const_iterator>.

Expression semantics

Name	Expression	Semantics	Postcondition
Default constructor	X() X a;	Creates an empty container, using key_compare() as the comparison object.	The size of the container is 0.
Constructor with compare	X(c) X a(c);	Creates an empty container, using c as the comparison object.	The size of the container is 0. key_comp () returns a function object that is equivalent to c.
Key comparison	a.key_comp()	Returns the key comparison object used by a.
Value comparison	a::value_compare()	Returns the value comparison object used by a.