Index: libcxx/trunk/include/algorithm =================================================================== --- libcxx/trunk/include/algorithm +++ libcxx/trunk/include/algorithm @@ -1418,7 +1418,11 @@ for (_ForwardIterator1 __i = __first1; __i != __last1; ++__i) { // Have we already counted the number of *__i in [f1, l1)? - if (find(__first1, __i, *__i) == __i) { + _ForwardIterator1 __match = __first1; + for (; __match != __i; ++__match) + if (__pred(*__match, *__i)) + break; + if (__match == __i) { // Count number of *__i in [f2, l2) _D1 __c2 = 0; for (_ForwardIterator2 __j = __first2; __j != __last2; ++__j) @@ -1479,7 +1483,11 @@ for (_ForwardIterator1 __i = __first1; __i != __last1; ++__i) { // Have we already counted the number of *__i in [f1, l1)? - if (find(__first1, __i, *__i) == __i) { + _ForwardIterator1 __match = __first1; + for (; __match != __i; ++__match) + if (__pred(*__match, *__i)) + break; + if (__match == __i) { // Count number of *__i in [f2, l2) _D1 __c2 = 0; for (_ForwardIterator2 __j = __first2; __j != __last2; ++__j) Index: libcxx/trunk/test/std/algorithms/alg.nonmodifying/alg.is_permutation/is_permutation_pred.pass.cpp =================================================================== --- libcxx/trunk/test/std/algorithms/alg.nonmodifying/alg.is_permutation/is_permutation_pred.pass.cpp +++ libcxx/trunk/test/std/algorithms/alg.nonmodifying/alg.is_permutation/is_permutation_pred.pass.cpp @@ -738,6 +738,30 @@ std::equal_to()) == false); #endif } + { + struct S { + S(int i) : i_(i) {} + bool operator==(const S& other) = delete; + int i_; + }; + struct eq { + bool operator()(const S& a, const S&b) { return a.i_ == b.i_; } + }; + const S a[] = {S(0), S(1)}; + const S b[] = {S(1), S(0)}; + const unsigned sa = sizeof(a)/sizeof(a[0]); + assert(std::is_permutation(forward_iterator(a), + forward_iterator(a + sa), + forward_iterator(b), + eq())); +#if TEST_STD_VER >= 14 + assert(std::is_permutation(forward_iterator(a), + forward_iterator(a + sa), + forward_iterator(b), + forward_iterator(b + sa), + eq())); +#endif + } #if TEST_STD_VER > 17 static_assert(test_constexpr());