boost的函数：is

template <typename InputIterator, typename UnaryPredicate> bool is_partitioned ( InputIterator first, InputIterator last, UnaryPredicate p ) { // Run through the part that satisfy the predicate for ( ; first != last; ++first ) if ( !p (*first)) break; // Now the part that does not satisfy the predicate for ( ; first != last; ++first ) if ( p (*first)) return false; return true; }

功能描述：

容器区间内的元素是否以函数P进行划分；容器区间元素分为两部分，第一部分满足函数要求，第二部分不满足函数要求。

示例：

bool isOdd(int i) {return i % 2 == 1;} bool lessThan10(int i){return i < 10;} int myints[] = {0, 1, 2, 3, 14, 15}; vector<int> c(myints, myints + sizeof(myints) / sizeof(int) ); is_partitioned ( c, isOdd ); //false is_partitioned ( c, lessThan10 ); //true is_partitioned ( c.begin (), c.end (), lessThan10 ); //true is_partitioned ( c.begin (), c.begin () + 3, lessThan10 ); //true is_partitioned ( c.end (), c.end (), isOdd ); //true:empty range