Fix PR#35948: generate_n does not accept floating point Size arguments.

git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@319675 91177308-0d34-0410-b5e6-96231b3b80d8

include/type_traits

@@ -4652,6 +4652,11 @@ long long __convert_to_integral(long long __val) { return __val; }
 inline _LIBCPP_INLINE_VISIBILITY
 unsigned long long __convert_to_integral(unsigned long long __val) {return __val; }
 
+template<typename _Fp>
+inline _LIBCPP_INLINE_VISIBILITY
+typename enable_if<is_floating_point<_Fp>::value, long long>::type
+ __convert_to_integral(_Fp __val) { return __val; }
+
 #ifndef _LIBCPP_HAS_NO_INT128
 inline _LIBCPP_INLINE_VISIBILITY
 __int128_t __convert_to_integral(__int128_t __val) { return __val; }

test/std/algorithms/alg.modifying.operations/alg.generate/generate_n.pass.cpp

@@ -18,29 +18,42 @@
 #include <algorithm>
 #include <cassert>
 
+#include "test_macros.h"
 #include "test_iterators.h"
 #include "user_defined_integral.hpp"
 
-typedef UserDefinedIntegral<unsigned> UDI;
-
 struct gen_test
 {
     int operator()() const {return 2;}
 };
 
-template <class Iter>
+template <class Iter, class Size>
 void
-test()
+test2()
 {
     const unsigned n = 4;
     int ia[n] = {0};
-    assert(std::generate_n(Iter(ia), UDI(n), gen_test()) == Iter(ia+n));
+    assert(std::generate_n(Iter(ia), Size(n), gen_test()) == Iter(ia+n));
     assert(ia[0] == 2);
     assert(ia[1] == 2);
     assert(ia[2] == 2);
     assert(ia[3] == 2);
 }
 
+template <class Iter>
+void
+test()
+{
+    test2<Iter, int>();
+    test2<Iter, unsigned int>();
+    test2<Iter, long>();
+    test2<Iter, unsigned long>();
+    test2<Iter, UserDefinedIntegral<unsigned> >();
+    test2<Iter, float>();
+    test2<Iter, double>();  // this is PR#35498
+    test2<Iter, long double>();
+}
+
 int main()
 {
     test<forward_iterator<int*> >();