STL之迭代器

容器支持的迭代器类型 

STL Container	Type of Iterators Supported
vector	random access iterators	元素严格有序（类似数组）
deque	random access iterators
list	bidirectional iterators	仅能通过某个 元素找到其直 接前驱和直接 后继（类似链 表）
set	bidirectional iterators
multiset	bidirectional iterators
map	bidirectional iterators
multimap	bidirectional iterators
stack	no iterator support
queue	no iterator support
priority_queue	no iterator support

迭代器支持的运算符

类别	运算符	描述
All iterators	++p	Preincrementan iterator. 前置自增
	p++	Postincrementan iterator. 后置自增
Input iterators	*p	Dereference an iterator (used as rvalue).迭代器解引用(仅做右值)
	p1 == p2	Evaluates true if p1 and p2 point to the same element.
	p1 != p2	Evaluates true if p1 and p2 point to different elements.
Output iterators	*p	Dereference an iterator (used as lvalue).迭代器解引用(仅做左值)
Bidirectionliterators	--p	Predecrementan iterator. 前置自减
	p--	Postdecrementan iterator. 后置自减
Random-access iterators	p += i	Increment iterator p by ipositions.
	p -= i	Decrement iterator p by i positions.
	p + i	Returns an iterator ith position after p.
	p - i	Returns an iterator ithposition before p.
	p1 < p2	Returns true if p1 is before p2.
	p1 <= p2	Returns true if p1 is before or equal to p2.
	p1 > p2	Returns true if p1 is after p2.
	p1 >= p2	Returns true if p1 is after p2 or equal to p2.
	p[i]	Returns the element at the position p offset by i.