// Stack implementation -*- C++ -*-
// Copyright (C) 2001-2020 Free Software Foundation, Inc.
//
// This file is part of the GNU ISO C++ Library. This library is free
// software; you can redistribute it and/or modify it under the
// terms of the GNU General Public License as published by the
// Free Software Foundation; either version 3, or (at your option)
// any later version.
// This library is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU General Public License for more details.
// Under Section 7 of GPL version 3, you are granted additional
// permissions described in the GCC Runtime Library Exception, version
// 3.1, as published by the Free Software Foundation.
// You should have received a copy of the GNU General Public License and
// a copy of the GCC Runtime Library Exception along with this program;
// see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
// <http://www.gnu.org/licenses/>.
/*
*
* Copyright (c) 1994
* Hewlett-Packard Company
*
* Permission to use, copy, modify, distribute and sell this software
* and its documentation for any purpose is hereby granted without fee,
* provided that the above copyright notice appear in all copies and
* that both that copyright notice and this permission notice appear
* in supporting documentation. Hewlett-Packard Company makes no
* representations about the suitability of this software for any
* purpose. It is provided "as is" without express or implied warranty.
*
*
* Copyright (c) 1996,1997
* Silicon Graphics Computer Systems, Inc.
*
* Permission to use, copy, modify, distribute and sell this software
* and its documentation for any purpose is hereby granted without fee,
* provided that the above copyright notice appear in all copies and
* that both that copyright notice and this permission notice appear
* in supporting documentation. Silicon Graphics makes no
* representations about the suitability of this software for any
* purpose. It is provided "as is" without express or implied warranty.
*/
/** @file bits/stl_stack.h
* This is an internal header file, included by other library headers.
* Do not attempt to use it directly. @headername{stack}
*/
#ifndef _STL_STACK_H
#define _STL_STACK_H 1
#include <bits/concept_check.h>
#include <debug/debug.h>
#if __cplusplus >= 201103L
# include <bits/uses_allocator.h>
#endif
namespace std _GLIBCXX_VISIBILITY(default)
{
_GLIBCXX_BEGIN_NAMESPACE_VERSION
/**
* @brief A standard container giving FILO behavior.
*
* @ingroup sequences
*
* @tparam _Tp Type of element.
* @tparam _Sequence Type of underlying sequence, defaults to deque<_Tp>.
*
* Meets many of the requirements of a
* <a href="tables.html#65">container</a>,
* but does not define anything to do with iterators. Very few of the
* other standard container interfaces are defined.
*
* This is not a true container, but an @e adaptor. It holds
* another container, and provides a wrapper interface to that
* container. The wrapper is what enforces strict
* first-in-last-out %stack behavior.
*
* The second template parameter defines the type of the underlying
* sequence/container. It defaults to std::deque, but it can be
* any type that supports @c back, @c push_back, and @c pop_back,
* such as std::list, std::vector, or an appropriate user-defined
* type.
*
* Members not found in @a normal containers are @c container_type,
* which is a typedef for the second Sequence parameter, and @c
* push, @c pop, and @c top, which are standard %stack/FILO
* operations.
*/
template<typename _Tp, typename _Sequence = deque<_Tp> >
class stack
{
#ifdef _GLIBCXX_CONCEPT_CHECKS
// concept requirements
typedef typename _Sequence::value_type _Sequence_value_type;
# if __cplusplus < 201103L
__glibcxx_class_requires(_Tp, _SGIAssignableConcept)
__glibcxx_class_requires(_Sequence, _BackInsertionSequenceConcept)
# endif
__glibcxx_class_requires2(_Tp, _Sequence_value_type, _SameTypeConcept)
#endif
template<typename _Tp1, typename _Seq1>
friend bool
operator==(const stack<_Tp1, _Seq1>&, const stack<_Tp1, _Seq1>&);
template<typename _Tp1, typename _Seq1>
friend bool
operator<(const stack<_Tp1, _Seq1>&, const stack<_Tp1, _Seq1>&);
#if __cpp_lib_three_way_comparison
template<typename _Tp1, three_way_comparable _Seq1>
friend compare_three_way_result_t<_Seq1>
operator<=>(const stack<_Tp1, _Seq1>&, const stack<_Tp1, _Seq1>&);
#endif
#if __cplusplus >= 201103L
template<typename _Alloc>
using _Uses = typename
enable_if<uses_allocator<_Sequence, _Alloc>::value>::type;
#if __cplusplus >= 201703L
// _GLIBCXX_RESOLVE_LIB_DEFECTS
// 2566. Requirements on the first template parameter of container
// adaptors
static_assert(is_same<_Tp, typename _Sequence::value_type>::value,
"value_type must be the same as the underlying container");
#endif // C++17
#endif // C++11
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 this name.
_Sequence c;
public:
// XXX removed old def ctor, added def arg to this one to match 14882
/**
* @brief Default constructor creates no elements.
*/
#if __cplusplus < 201103L
explicit
stack(const _Sequence& __c = _Sequence())
: c(__c) { }
#else
template<typename _Seq = _Sequence, typename _Requires = typename
enable_if<is_default_constructible<_Seq>::value>::type>
stack()
: c() { }
explicit
stack(const _Sequence& __c)
: c(__c) { }
explicit
stack(_Sequence&& __c)
: c(std::move(__c)) { }
template<typename _Alloc, typename _Requires = _Uses<_Alloc>>
explicit
stack(const _Alloc& __a)
: c(__a) { }
template<typename _Alloc, typename _Requires = _Uses<_Alloc>>
stack(const _Sequence& __c, const _Alloc& __a)
: c(__c, __a) { }
template<typename _Alloc, typename _Requires = _Uses<_Alloc>>
stack(_Sequence&& __c, const _Alloc& __a)
: c(std::move(__c), __a) { }
template<typename _Alloc, typename _Requires = _Uses<_Alloc>>
stack(const stack& __q, const _Alloc& __a)
: c(__q.c, __a) { }
template<typename _Alloc, typename _Requires = _Uses<_Alloc>>
stack(stack&& __q, const _Alloc& __a)
: c(std::move(__q.c), __a) { }
#endif
/**
* Returns true if the %stack is empty.
*/
_GLIBCXX_NODISCARD bool
empty() const
{ return c.empty(); }
/** Returns the number of elements in the %stack. */
size_type
size() const
{ return c.size(); }
/**
* Returns a read/write reference to the data at the first
* element of the %stack.
*/
reference
top()
{
__glibcxx_requires_nonempty();
return c.back();
}
/**
* Returns a read-only (constant) reference to the data at the first
* element of the %stack.
*/
const_reference
top() const
{
__glibcxx_requires_nonempty();
return c.back();
}
/**
* @brief Add data to the top of the %stack.
* @param __x Data to be added.
*
* This is a typical %stack operation. The function creates an
* element at the top of the %stack and assigns the given data
* to it. The time complexity of the operation depends on the
* underlying sequence.
*/
void
push(const value_type& __x)
{ c.push_back(__x); }
#if __cplusplus >= 201103L
void
push(value_type&& __x)
{ c.push_back(std::move(__x)); }
#if __cplusplus > 201402L
template<typename... _Args>
decltype(auto)
emplace(_Args&&... __args)
{ return c.emplace_back(std::forward<_Args>(__args)...); }
#else
template<typename... _Args>
void
emplace(_Args&&... __args)
{ c.emplace_back(std::forward<_Args>(__args)...); }
#endif
#endif
/**
* @brief Removes first element.
*
* This is a typical %stack operation. It shrinks the %stack
* by one. The time complexity of the operation depends on the
* underlying sequence.
*
* Note that no data is returned, and if the first element's
* data is needed, it should be retrieved before pop() is
* called.
*/
void
pop()
{
__glibcxx_requires_nonempty();
c.pop_back();
}
#if __cplusplus >= 201103L
void
swap(stack& __s)
#if __cplusplus > 201402L || !defined(__STRICT_ANSI__) // c++1z or gnu++11
noexcept(__is_nothrow_swappable<_Sequence>::value)
#else
noexcept(__is_nothrow_swappable<_Tp>::value)
#endif
{
using std::swap;
swap(c, __s.c);
}
#endif // __cplusplus >= 201103L
};
#if __cpp_deduction_guides >= 201606
template<typename _Container,
typename = _RequireNotAllocator<_Container>>
stack(_Container) -> stack<typename _Container::value_type, _Container>;
template<typename _Container, typename _Allocator,
typename = _RequireNotAllocator<_Container>,
typename = _RequireAllocator<_Allocator>>
stack(_Container, _Allocator)
-> stack<typename _Container::value_type, _Container>;
#endif
/**
* @brief Stack equality comparison.
* @param __x A %stack.
* @param __y A %stack of the same type as @a __x.
* @return True iff the size and elements of the stacks are equal.
*
* This is an equivalence relation. Complexity and semantics
* depend on the underlying sequence type, but the expected rules
* are: this relation is linear in the size of the sequences, and
* stacks are considered equivalent if their sequences compare
* equal.
*/
template<typename _Tp, typename _Seq>
inline bool
operator==(const stack<_Tp, _Seq>& __x, const stack<_Tp, _Seq>& __y)
{ return __x.c == __y.c; }
/**
* @brief Stack ordering relation.
* @param __x A %stack.
* @param __y A %stack of the same type as @a x.
* @return True iff @a x is lexicographically less than @a __y.
*
* This is an total ordering relation. Complexity and semantics
* depend on the underlying sequence type, but the expected rules
* are: this relation is linear in the size of the sequences, the
* elements must be comparable with @c <, and
* std::lexicographical_compare() is usually used to make the
* determination.
*/
template<typename _Tp, typename _Seq>
inline bool
operator<(const stack<_Tp, _Seq>& __x, const stack<_Tp, _Seq>& __y)
{ return __x.c < __y.c; }
/// Based on operator==
template<typename _Tp, typename _Seq>
inline bool
operator!=(const stack<_Tp, _Seq>& __x, const stack<_Tp, _Seq>& __y)
{ return !(__x == __y); }
/// Based on operator<
template<typename _Tp, typename _Seq>
inline bool
operator>(const stack<_Tp, _Seq>& __x, const stack<_Tp, _Seq>& __y)
{ return __y < __x; }
/// Based on operator<
template<typename _Tp, typename _Seq>
inline bool
operator<=(const stack<_Tp, _Seq>& __x, const stack<_Tp, _Seq>& __y)
{ return !(__y < __x); }
/// Based on operator<
template<typename _Tp, typename _Seq>
inline bool
operator>=(const stack<_Tp, _Seq>& __x, const stack<_Tp, _Seq>& __y)
{ return !(__x < __y); }
#if __cpp_lib_three_way_comparison
template<typename _Tp, three_way_comparable _Seq>
inline compare_three_way_result_t<_Seq>
operator<=>(const stack<_Tp, _Seq>& __x, const stack<_Tp, _Seq>& __y)
{ return __x.c <=> __y.c; }
#endif
#if __cplusplus >= 201103L
template<typename _Tp, typename _Seq>
inline
#if __cplusplus > 201402L || !defined(__STRICT_ANSI__) // c++1z or gnu++11
// Constrained free swap overload, see p0185r1
typename enable_if<__is_swappable<_Seq>::value>::type
#else
void
#endif
swap(stack<_Tp, _Seq>& __x, stack<_Tp, _Seq>& __y)
noexcept(noexcept(__x.swap(__y)))
{ __x.swap(__y); }
template<typename _Tp, typename _Seq, typename _Alloc>
struct uses_allocator<stack<_Tp, _Seq>, _Alloc>
: public uses_allocator<_Seq, _Alloc>::type { };
#endif // __cplusplus >= 201103L
_GLIBCXX_END_NAMESPACE_VERSION
} // namespace
#endif /* _STL_STACK_H */