clamp:
template<typename T, typename Pred> T const & clamp ( T const& val, typename boost::mpl::identity<T>::type const & lo, typename boost::mpl::identity<T>::type const & hi, Pred p ) { // assert ( !p ( hi, lo )); // Can't assert p ( lo, hi ) b/c they might be equal return p ( val, lo ) ? lo : p ( hi, val ) ? hi : val; } 简述：给定三个数，返回中间数（Pred默认使用std::less)。示例：
int foo = 23; foo = boost::algorithm::clamp(foo, 1, 10); cout << foo << endl; gather: template < typename BidirectionalIterator, // Iter models BidirectionalIterator typename Pred> // Pred models UnaryPredicate std::pair<BidirectionalIterator, BidirectionalIterator> gather ( BidirectionalIterator first, BidirectionalIterator last, BidirectionalIterator pivot, Pred pred ) { // The first call partitions everything up to (but not including) the pivot element, // while the second call partitions the rest of the sequence. return std::make_pair ( std::stable_partition ( first, pivot, !boost::bind<bool> ( pred, _1 )), std::stable_partition ( pivot, last, boost::bind<bool> ( pred, _1 ))); } 简述：将容器中满足pred函数要求的元素聚集到pivot的两边，并返回满足元素的区间迭代器。
stable_partition函数作用是依据pred函数将容器分为两部分(前一部分满足函数要求，后一部分不满足函数要求),且元素的相对位置不发生变化。
示例：
int arr[] = {0, 1, 2, 3, 4, 5, 6, 7, 8, 9}; auto range = boost::algorithm::gather(arr, arr + 10, arr + 4, isEven); //1 3 0 2 4 6 8 5 7 9 for(auto i = 0; i < sizeof(arr) / sizeof(int); ++i) { cout << *(arr + i) << " "; } cout << endl; //0 2 4 6 8 for(auto ite = range.first; ite != range.second; ++ite) { cout << *ite << " "; } cout << endl;hex:
is_palindrome:
