fix missing &

Author: c8ef

libcxx/include/__algorithm/generate.h

@@ -22,7 +22,7 @@ _LIBCPP_BEGIN_NAMESPACE_STD
 
 template <class _ForwardIterator, class _Sent, class _Generator>
 inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 void
-__generate(_ForwardIterator __first, _Sent __last, _Generator __gen) {
+__generate(_ForwardIterator __first, _Sent __last, _Generator& __gen) {
   for (; __first != __last; ++__first)
     *__first = __gen();
 }

libcxx/test/libcxx/algorithms/robust_against_copying_comparators.pass.cpp

@@ -149,8 +149,7 @@ TEST_CONSTEXPR_CXX20 bool all_the_algorithms() {
   assert(copies == 0);
 #endif
   (void)std::generate(first, last, NullaryValue<T>(&copies));
-  assert(copies == 1);
-  copies = 0;
+  assert(copies == 0);
   (void)std::generate_n(first, count, NullaryValue<T>(&copies));
   assert(copies == 0);
   (void)std::includes(first, last, first2, last2, Less<T>(&copies));