C++进阶——STL源码之顺序容器适配器
顺序容器适配器
容器适配器是一种利用存在的容器类型采用另一种不同的抽象类型的工作方式实现。
stack
stack是一种先进后出的数据结构，它只有一个出口；stack允许新增元素、移除元素、取得最顶端的元素；但是除了顶端外不可以存取其他元素；stack没有迭代器。
stack在缺省的情况下是以deque作为底部容器来完成所有的工作，元素的操作只有push 和 pop 两个接口。
stack也可以使用vector 、 list 、deque 作为底部容器。
template >
class stack
{
// concept requirements
typedef typename _Sequence::value_type _Sequence_value_type;
__glibcxx_class_requires(_Tp, _SGIAssignableConcept)
__glibcxx_class_requires(_Sequence, _BackInsertionSequenceConcept)
__glibcxx_class_requires2(_Tp, _Sequence_value_type, _SameTypeConcept)
template
friend bool
operator==(const stack<_Tp1, _Seq1>&, const stack<_Tp1, _Seq1>&);
template
friend bool
operator<(const stack<_Tp1, _Seq1>&, const stack<_Tp1, _Seq1>&);
public:
typedef typename _Sequence::value_type value_type;
typedef typename _Sequence::reference reference;
typedef typename _Sequence::const_reference const_reference;
typedef typename _Sequence::size_type size_type;
typedef _Sequence container_type;
protected:
.
_Sequence c;
public:
explicit
stack(const _Sequence& __c = _Sequence())
: c(__c) { }
bool
empty() const
{
return c.empty();
}
size_type
size() const
{
return c.size();
}
reference
top()
{
__glibcxx_requires_nonempty();
return c.back();
}
const_reference
top() const
{
__glibcxx_requires_nonempty();
return c.back();
}
void
push(const value_type& __x)
{
c.push_back(__x);
}
void
pop()
{
__glibcxx_requires_nonempty();
c.pop_back();
}
}; queue
queue是一种先进先出的数据结构，他有两个接口；queue允许新增元素、移除元素、从最低端加入元素、从最顶端取得元素；queue也没有迭代器。
queue缺省的情况下以deque作为底部容器实现；
queue可以使用 deque 、 list 作为底部实现容器。
template >
class queue
{
// concept requirements
typedef typename _Sequence::value_type _Sequence_value_type;
__glibcxx_class_requires(_Tp, _SGIAssignableConcept)
__glibcxx_class_requires(_Sequence, _FrontInsertionSequenceConcept)
__glibcxx_class_requires(_Sequence, _BackInsertionSequenceConcept)
__glibcxx_class_requires2(_Tp, _Sequence_value_type, _SameTypeConcept)
template
friend bool
operator==(const queue<_Tp1, _Seq1>&, const queue<_Tp1, _Seq1>&);
template
friend bool
operator<(const queue<_Tp1, _Seq1>&, const queue<_Tp1, _Seq1>&);
public:
typedef typename _Sequence::value_type value_type;
typedef typename _Sequence::reference reference;
typedef typename _Sequence::const_reference const_reference;
typedef typename _Sequence::size_type size_type;
typedef _Sequence container_type;
protected:
_Sequence c;
public:
explicit
queue(const _Sequence& __c = _Sequence())
: c(__c) { }
/**
* Returns true if the %queue is empty.
*/
bool
empty() const
{
return c.empty();
}
/** Returns the number of elements in the %queue. */
size_type
size() const
{
return c.size();
}
/**
* Returns a read/write reference to the data at the first
* element of the %queue.
*/
reference
front()
{
__glibcxx_requires_nonempty();
return c.front();
}
/**
* Returns a read-only (constant) reference to the data at the first
* element of the %queue.
*/
const_reference
front() const
{
__glibcxx_requires_nonempty();
return c.front();
}
/**
* Returns a read/write reference to the data at the last
* element of the %queue.
*/
reference
back()
{
__glibcxx_requires_nonempty();
return c.back();
}
/**
* Returns a read-only (constant) reference to the data at the last
* element of the %queue.
*/
const_reference
back() const
{
__glibcxx_requires_nonempty();
return c.back();
}
void
push(const value_type& __x)
{
c.push_back(__x);
}
void
pop()
{
__glibcxx_requires_nonempty();
c.pop_front();
}
};
priority_queue
priority_queue是一个拥有权值观念的queue，它允许加入新的元素、移除旧元素、审视元素等功能；
priority_queue也是一种queue，它只允许在底部加入元素，在顶部取出元素；
priority_queue缺省的情况下是以vector作为底部容器实现；
priority_queue 没有迭代器。
template,
typename _Compare = less >
class priority_queue
{
// concept requirements
typedef typename _Sequence::value_type _Sequence_value_type;
__glibcxx_class_requires(_Tp, _SGIAssignableConcept)
__glibcxx_class_requires(_Sequence, _SequenceConcept)
__glibcxx_class_requires(_Sequence, _RandomAccessContainerConcept)
__glibcxx_class_requires2(_Tp, _Sequence_value_type, _SameTypeConcept)
__glibcxx_class_requires4(_Compare, bool, _Tp, _Tp,
_BinaryFunctionConcept)
public:
typedef typename _Sequence::value_type value_type;
typedef typename _Sequence::reference reference;
typedef typename _Sequence::const_reference const_reference;
typedef typename _Sequence::size_type size_type;
typedef _Sequence container_type;
protected:
// See queue::c for notes on these names.
_Sequence c;
_Compare comp;
public:
explicit
priority_queue(const _Compare& __x = _Compare(),
const _Sequence& __s = _Sequence())
: c(__s), comp(__x)
{
std::make_heap(c.begin(), c.end(), comp);
}
template
priority_queue(_InputIterator __first, _InputIterator __last,
const _Compare& __x = _Compare(),
const _Sequence& __s = _Sequence())
: c(__s), comp(__x)
{
__glibcxx_requires_valid_range(__first, __last);
c.insert(c.end(), __first, __last);
std::make_heap(c.begin(), c.end(), comp);
}
/**
* Returns true if the %queue is empty.
*/
bool
empty() const
{
return c.empty();
}
/** Returns the number of elements in the %queue. */
size_type
size() const
{
return c.size();
}
/**
* Returns a read-only (constant) reference to the data at the first
* element of the %queue.
*/
const_reference
top() const
{
__glibcxx_requires_nonempty();
return c.front();
}
void
push(const value_type& __x)
{
c.push_back(__x);
std::push_heap(c.begin(), c.end(), comp);
}
void
pop()
{
__glibcxx_requires_nonempty();
std::pop_heap(c.begin(), c.end(), comp);
c.pop_back();
}
};