C++ Notes: STL: Iterator Operators

Assume C is a container class, containing elements of type T.

bool b;
int i;
T value;
C::iterator it, it1, it2;

Result	Operator	Description
Operators for most iterators. Vectors, lists, arrays, ....
`value =`	`*it;`	Use dereference (*) op to get/set value.
	`++it;`	Points to next element. Value after update.
	`it++;`	Points to next element. Value before update.
`it1 =`	`it2;`	Assignment
`b =`	`it1 == it2;`	Equality comparison.
`b =`	`it1 != it2;`	Inequality.
Additional operators for bidirectional iterators. Vectors, lists, arrays, ...
	`--it;`	Predecrement.
	`it--;`	Postdecrement. May be less efficient than predecrement.
Additional operators for random-access iterators. Vectors and arrays, but not lists.
`it +=`	`i;`	Increments it by i positions.
`it -=`	`i;`	Decrements it by i positions.
`it1 =`	`it2 + i;`	Increments it by i positions.
`it1 =`	`it2 - i;`	Decrements it by i positions.
`value =`	`it[i];`	Returns reference to ith element after it.
`b =`	`it1 < it2;`	Comparison.
`b =`	`it1 <= it2;`	Comparison.
`b =`	`it1 > it2;`	Comparison.
`b =`	`it1 <= it2;`	Comparison.