1 //===----------------------------------------------------------------------===// 2 // 3 // The LLVM Compiler Infrastructure 4 // 5 // This file is dual licensed under the MIT and the University of Illinois Open 6 // Source Licenses. See LICENSE.TXT for details. 7 // 8 //===----------------------------------------------------------------------===// 9 10 // <algorithm> 11 12 // template<class Iter, IntegralLike Size, Callable Generator> 13 // requires OutputIterator<Iter, Generator::result_type> 14 // && CopyConstructible<Generator> 15 // constexpr void // constexpr after c++17 16 // generate_n(Iter first, Size n, Generator gen); 17 18 #ifdef _MSC_VER 19 #pragma warning(disable: 4244) // conversion from 'const double' to 'int', possible loss of data 20 #endif 21 22 #include <algorithm> 23 #include <cassert> 24 25 #include "test_macros.h" 26 #include "test_iterators.h" 27 #include "user_defined_integral.hpp" 28 29 struct gen_test 30 { 31 TEST_CONSTEXPR int operator()() const {return 2;} 32 }; 33 34 35 #if TEST_STD_VER > 17 36 TEST_CONSTEXPR bool test_constexpr() { 37 const size_t N = 5; 38 int ib[] = {0, 0, 0, 0, 0, 0}; // one bigger than N 39 40 auto it = std::generate_n(std::begin(ib), N, gen_test()); 41 42 return it == (std::begin(ib) + N) 43 && std::all_of(std::begin(ib), it, [](int x) { return x == 2; }) 44 && *it == 0 // don't overwrite the last value in the output array 45 ; 46 } 47 #endif 48 49 50 template <class Iter, class Size> 51 void 52 test2() 53 { 54 const unsigned n = 4; 55 int ia[n] = {0}; 56 assert(std::generate_n(Iter(ia), Size(n), gen_test()) == Iter(ia+n)); 57 assert(ia[0] == 2); 58 assert(ia[1] == 2); 59 assert(ia[2] == 2); 60 assert(ia[3] == 2); 61 } 62 63 template <class Iter> 64 void 65 test() 66 { 67 test2<Iter, int>(); 68 test2<Iter, unsigned int>(); 69 test2<Iter, long>(); 70 test2<Iter, unsigned long>(); 71 test2<Iter, UserDefinedIntegral<unsigned> >(); 72 test2<Iter, float>(); 73 test2<Iter, double>(); // this is PR#35498 74 test2<Iter, long double>(); 75 } 76 77 int main() 78 { 79 test<forward_iterator<int*> >(); 80 test<bidirectional_iterator<int*> >(); 81 test<random_access_iterator<int*> >(); 82 test<int*>(); 83 84 #if TEST_STD_VER > 17 85 static_assert(test_constexpr()); 86 #endif 87 } 88