From ccd4c3fca513db530e0be91e4830df6e6c0555f4 Mon Sep 17 00:00:00 2001 From: Peng Wu Date: Sat, 1 Sep 2012 11:27:18 +0800 Subject: [PATCH] refactor stl_lite.h --- src/include/stl_lite.h | 287 +++---------------------------------------------- 1 file changed, 12 insertions(+), 275 deletions(-) diff --git a/src/include/stl_lite.h b/src/include/stl_lite.h index c9f7c88..e7b960b 100644 --- a/src/include/stl_lite.h +++ b/src/include/stl_lite.h @@ -4,298 +4,35 @@ #include #include #include +#include namespace std_lite{ + /** + * To restrict the usage of STL functions in libpinyin, + * all needed functions should be imported here. + */ - /** - * @brief This does what you think it does. - * @param a A thing of arbitrary type. - * @param b Another thing of arbitrary type. - * @return The lesser of the parameters. - * - * This is the simple classic generic implementation. It will work on - * temporary expressions, since they are only evaluated once, unlike a - * preprocessor macro. - */ - template - inline const _Tp& - min(const _Tp& __a, const _Tp& __b) - { - //return __b < __a ? __b : __a; - if (__b < __a) - return __b; - return __a; - } + using std::min; - /** - * @brief This does what you think it does. - * @param a A thing of arbitrary type. - * @param b Another thing of arbitrary type. - * @return The greater of the parameters. - * - * This is the simple classic generic implementation. It will work on - * temporary expressions, since they are only evaluated once, unlike a - * preprocessor macro. - */ - template - inline const _Tp& - max(const _Tp& __a, const _Tp& __b) - { - //return __a < __b ? __b : __a; - if (__a < __b) - return __b; - return __a; - } + using std::max; - /** - * @brief Swaps two values. - * @ingroup mutating_algorithms - * @param __a A thing of arbitrary type. - * @param __b Another thing of arbitrary type. - * @return Nothing. - */ - template - inline void - swap(_Tp& __a, _Tp& __b) - { - _Tp __tmp = __a; - __a = __b; - __b = __tmp; - } + using std::pair; - /** - * This is one of the @link s20_3_1_base functor base classes@endlink. - */ - template - struct binary_function - { - typedef _Arg1 first_argument_type; ///< the type of the first argument - /// (no surprises here) - typedef _Arg2 second_argument_type; ///< the type of the second argument - typedef _Result result_type; ///< type of the return type - }; + using std::make_pair; - /// pair holds two objects of arbitrary type. - template - struct pair - { - typedef _T1 first_type; ///< @c first_type is the first bound type - typedef _T2 second_type; ///< @c second_type is the second bound type + using std::lower_bound; - _T1 first; ///< @c first is a copy of the first object - _T2 second; ///< @c second is a copy of the second object - /** The default constructor creates @c first and @c second using their - * respective default constructors. */ - pair() - : first(), second() { } + using std::upper_bound; - /** Two objects may be passed to a @c pair constructor to be copied. */ - pair(const _T1& __a, const _T2& __b) - : first(__a), second(__b) { } - /** There is also a templated copy ctor for the @c pair class itself. */ - template - pair(const pair<_U1, _U2>& __p) - : first(__p.first), second(__p.second) { } - }; - - /// Two pairs of the same type are equal iff their members are equal. - template - inline bool - operator==(const pair<_T1, _T2>& __x, const pair<_T1, _T2>& __y) - { return __x.first == __y.first && __x.second == __y.second; } - - /// - template - inline bool - operator<(const pair<_T1, _T2>& __x, const pair<_T1, _T2>& __y) - { return __x.first < __y.first - || (!(__y.first < __x.first) && __x.second < __y.second); } - - /// Uses @c operator== to find the result. - template - inline bool - operator!=(const pair<_T1, _T2>& __x, const pair<_T1, _T2>& __y) - { return !(__x == __y); } - - /// Uses @c operator< to find the result. - template - inline bool - operator>(const pair<_T1, _T2>& __x, const pair<_T1, _T2>& __y) - { return __y < __x; } - - /// Uses @c operator< to find the result. - template - inline bool - operator<=(const pair<_T1, _T2>& __x, const pair<_T1, _T2>& __y) - { return !(__y < __x); } - - /// Uses @c operator< to find the result. - template - inline bool - operator>=(const pair<_T1, _T2>& __x, const pair<_T1, _T2>& __y) - { return !(__x < __y); } - - /** - * @brief A convenience wrapper for creating a pair from two objects. - * @param x The first object. - * @param y The second object. - * @return A newly-constructed pair<> object of the appropriate type. - * - * The standard requires that the objects be passed by reference-to-const, - * but LWG issue #181 says they should be passed by const value. We follow - * the LWG by default. - */ - // _GLIBCXX_RESOLVE_LIB_DEFECTS - // 181. make_pair() unintended behavior - template - inline pair<_T1, _T2> - make_pair(_T1 __x, _T2 __y) - { return pair<_T1, _T2>(__x, __y); } - - /** - * @brief Finds the first position in which @a val could be inserted - * without changing the ordering. - * @param first An iterator. - * @param last Another iterator. - * @param val The search term. - * @param comp A functor to use for comparisons. - * @return An iterator pointing to the first element "not less than" @a val, - * or end() if every element is less than @a val. - * @ingroup binarysearch - * - * The comparison function should have the same effects on ordering as - * the function used for the initial sort. - */ - template - _ForwardIterator - lower_bound(_ForwardIterator __first, _ForwardIterator __last, - const _Tp& __val, _Compare __comp) - { - typedef size_t _DistanceType; - - _DistanceType __len = __last - __first; - _DistanceType __half; - _ForwardIterator __middle; - - while (__len > 0) - { - __half = __len >> 1; - __middle = __first; - __middle += __half; - if (__comp(*__middle, __val)) - { - __first = __middle; - ++__first; - __len = __len - __half - 1; - } - else - __len = __half; - } - return __first; - } - - /** - * @brief Finds the last position in which @a val could be inserted - * without changing the ordering. - * @param first An iterator. - * @param last Another iterator. - * @param val The search term. - * @param comp A functor to use for comparisons. - * @return An iterator pointing to the first element greater than @a val, - * or end() if no elements are greater than @a val. - * @ingroup binarysearch - * - * The comparison function should have the same effects on ordering as - * the function used for the initial sort. - */ - template - _ForwardIterator - upper_bound(_ForwardIterator __first, _ForwardIterator __last, - const _Tp& __val, _Compare __comp) - { - typedef size_t _DistanceType; - _DistanceType __len = __last - __first; - _DistanceType __half; - _ForwardIterator __middle; - - while (__len > 0) - { - __half = __len >> 1; - __middle = __first; - __middle += __half; - if (__comp(__val, *__middle)) - __len = __half; - else - { - __first = __middle; - ++__first; - __len = __len - __half - 1; - } - } - return __first; - } - - /** - * @brief Finds the largest subrange in which @a val could be inserted - * at any place in it without changing the ordering. - * @param first An iterator. - * @param last Another iterator. - * @param val The search term. - * @param comp A functor to use for comparisons. - * @return An pair of iterators defining the subrange. - * @ingroup binarysearch - * - * This is equivalent to - * @code - * std_lite::make_pair(lower_bound(first, last, val, comp), - * upper_bound(first, last, val, comp)) - * @endcode - * but does not actually call those functions. - */ - template - pair<_ForwardIterator, _ForwardIterator> - equal_range(_ForwardIterator __first, _ForwardIterator __last, - const _Tp& __val, - _Compare __comp) - { - - typedef size_t _DistanceType; - - _DistanceType __len = __last - __first; - _DistanceType __half; - _ForwardIterator __middle, __left, __right; - - while (__len > 0) - { - __half = __len >> 1; - __middle = __first; - __middle += __half; - if (__comp(*__middle, __val)) - { - __first = __middle; - ++__first; - __len = __len - __half - 1; - } - else if (__comp(__val, *__middle)) - __len = __half; - else - { - __left = lower_bound(__first, __middle, __val, __comp); - __first += __len; - __right = upper_bound(++__middle, __first, __val, __comp); - return pair<_ForwardIterator, _ForwardIterator>(__left, __right); - } - } - return pair<_ForwardIterator, _ForwardIterator>(__first, __first); - } + using std::equal_range; } -- 2.7.4