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- // 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 */
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