c++ SGI STL源代码学习

/* * * 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 * 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. */ /* NOTE: This is an internal header file, included by other STL headers. * You should not attempt to use it directly. */ #ifndef __SGI_STL_INTERNAL_ALGO_H #define __SGI_STL_INTERNAL_ALGO_H #include <stl_heap.h> // See concept_checks.h for the concept-checking macros // __STL_REQUIRES, __STL_CONVERTIBLE, etc. __STL_BEGIN_NAMESPACE #if defined(__sgi) && !defined(__GNUC__) && (_MIPS_SIM != _MIPS_SIM_ABI32) #pragma set woff 1209 #endif // __median (an extension, not present in the C++ standard). template <class _Tp> inline const _Tp& __median(const _Tp& __a, const _Tp& __b, const _Tp& __c) { __STL_REQUIRES(_Tp, _LessThanComparable); if (__a < __b) if (__b < __c) return __b; else if (__a < __c) return __c; else return __a; else if (__a < __c) return __a; else if (__b < __c) return __c; else return __b; } template <class _Tp, class _Compare> inline const _Tp& __median(const _Tp& __a, const _Tp& __b, const _Tp& __c, _Compare __comp) { __STL_BINARY_FUNCTION_CHECK(_Compare, bool, _Tp, _Tp); if (__comp(__a, __b)) if (__comp(__b, __c)) return __b; else if (__comp(__a, __c)) return __c; else return __a; else if (__comp(__a, __c)) return __a; else if (__comp(__b, __c)) return __c; else return __b; } // for_each. Apply a function to every element of a range. template <class _InputIter, class _Function> _Function for_each(_InputIter __first, _InputIter __last, _Function __f) { __STL_REQUIRES(_InputIter, _InputIterator); for ( ; __first != __last; ++__first) __f(*__first); return __f; } // find and find_if. template <class _InputIter, class _Tp> inline _InputIter find(_InputIter __first, _InputIter __last, const _Tp& __val, input_iterator_tag) { while (__first != __last && !(*__first == __val)) ++__first; return __first; } template <class _InputIter, class _Predicate> inline _InputIter find_if(_InputIter __first, _InputIter __last, _Predicate __pred, input_iterator_tag) { while (__first != __last && !__pred(*__first)) ++__first; return __first; } #ifdef __STL_CLASS_PARTIAL_SPECIALIZATION template <class _RandomAccessIter, class _Tp> _RandomAccessIter find(_RandomAccessIter __first, _RandomAccessIter __last, const _Tp& __val, random_access_iterator_tag) { typename iterator_traits<_RandomAccessIter>::difference_type __trip_count = (__last - __first) >> 2; for ( ; __trip_count > 0 ; --__trip_count) { if (*__first == __val) return __first; ++__first; if (*__first == __val) return __first; ++__first; if (*__first == __val) return __first; ++__first; if (*__first == __val) return __first; ++__first; } switch(__last - __first) { case 3: if (*__first == __val) return __first; ++__first; case 2: if (*__first == __val) return __first; ++__first; case 1: if (*__first == __val) return __first; ++__first; case 0: default: return __last; } } template <class _RandomAccessIter, class _Predicate> _RandomAccessIter find_if(_RandomAccessIter __first, _RandomAccessIter __last, _Predicate __pred, random_access_iterator_tag) { typename iterator_traits<_RandomAccessIter>::difference_type __trip_count = (__last - __first) >> 2; for ( ; __trip_count > 0 ; --__trip_count) { if (__pred(*__first)) return __first; ++__first; if (__pred(*__first)) return __first; ++__first; if (__pred(*__first)) return __first; ++__first; if (__pred(*__first)) return __first; ++__first; } switch(__last - __first) { case 3: if (__pred(*__first)) return __first; ++__first; case 2: if (__pred(*__first)) return __first; ++__first; case 1: if (__pred(*__first)) return __first; ++__first; case 0: default: return __last; } } #endif /* __STL_CLASS_PARTIAL_SPECIALIZATION */ template <class _InputIter, class _Tp> inline _InputIter find(_InputIter __first, _InputIter __last, const _Tp& __val) { __STL_REQUIRES(_InputIter, _InputIterator); __STL_REQUIRES_BINARY_OP(_OP_EQUAL, bool, typename iterator_traits<_InputIter>::value_type, _Tp); return find(__first, __last, __val, __ITERATOR_CATEGORY(__first)); } template <class _InputIter, class _Predicate> inline _InputIter find_if(_InputIter __first, _InputIter __last, _Predicate __pred) { __STL_REQUIRES(_InputIter, _InputIterator); __STL_UNARY_FUNCTION_CHECK(_Predicate, bool, typename iterator_traits<_InputIter>::value_type); return find_if(__first, __last, __pred, __ITERATOR_CATEGORY(__first)); } // adjacent_find. template <class _ForwardIter> _ForwardIter adjacent_find(_ForwardIter __first, _ForwardIter __last) { __STL_REQUIRES(_ForwardIter, _ForwardIterator); __STL_REQUIRES(typename iterator_traits<_ForwardIter>::value_type, _EqualityComparable); if (__first == __last) return __last; _ForwardIter __next = __first; while(++__next != __last) { if (*__first == *__next) return __first; __first = __next; } return __last; } template <class _ForwardIter, class _BinaryPredicate> _ForwardIter adjacent_find(_ForwardIter __first, _ForwardIter __last, _BinaryPredicate __binary_pred) { __STL_REQUIRES(_ForwardIter, _ForwardIterator); __STL_BINARY_FUNCTION_CHECK(_BinaryPredicate, bool, typename iterator_traits<_ForwardIter>::value_type, typename iterator_traits<_ForwardIter>::value_type); if (__first == __last) return __last; _ForwardIter __next = __first; while(++__next != __last) { if (__binary_pred(*__first, *__next)) return __first; __first = __next; } return __last; } // count and count_if. There are two version of each, one whose return type // type is void and one (present only if we have partial specialization) // whose return type is iterator_traits<_InputIter>::difference_type. The // C++ standard only has the latter version, but the former, which was present // in the HP STL, is retained for backward compatibility. template <class _InputIter, class _Tp, class _Size> void count(_InputIter __first, _InputIter __last, const _Tp& __value, _Size& __n) { __STL_REQUIRES(_InputIter, _InputIterator); __STL_REQUIRES(typename iterator_traits<_InputIter>::value_type, _EqualityComparable); __STL_REQUIRES(_Tp, _EqualityComparable); for ( ; __first != __last; ++__first) if (*__first == __value) ++__n; } template <class _InputIter, class _Predicate, class _Size> void count_if(_InputIter __first, _InputIter __last, _Predicate __pred,