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 #include "test_macros.h" 19 20 #ifdef TEST_COMPILER_C1XX 21 #pragma warning(disable: 4244) // conversion from 'const double' to 'int', possible loss of data 22 #endif 23 24 #include <algorithm> 25 #include <cassert> 26 27 #include "test_iterators.h" 28 #include "user_defined_integral.hpp" 29 30 struct gen_test 31 { 32 TEST_CONSTEXPR int operator()() const {return 2;} 33 }; 34 35 36 #if TEST_STD_VER > 17 37 TEST_CONSTEXPR bool test_constexpr() { 38 const size_t N = 5; 39 int ib[] = {0, 0, 0, 0, 0, 0}; // one bigger than N 40 41 auto it = std::generate_n(std::begin(ib), N, gen_test()); 42 43 return it == (std::begin(ib) + N) 44 && std::all_of(std::begin(ib), it, [](int x) { return x == 2; }) 45 && *it == 0 // don't overwrite the last value in the output array 46 ; 47 } 48 #endif 49 50 51 template <class Iter, class Size> 52 void 53 test2() 54 { 55 const unsigned n = 4; 56 int ia[n] = {0}; 57 assert(std::generate_n(Iter(ia), Size(n), gen_test()) == Iter(ia+n)); 58 assert(ia[0] == 2); 59 assert(ia[1] == 2); 60 assert(ia[2] == 2); 61 assert(ia[3] == 2); 62 } 63 64 template <class Iter> 65 void 66 test() 67 { 68 test2<Iter, int>(); 69 test2<Iter, unsigned int>(); 70 test2<Iter, long>(); 71 test2<Iter, unsigned long>(); 72 test2<Iter, UserDefinedIntegral<unsigned> >(); 73 test2<Iter, float>(); 74 test2<Iter, double>(); // this is PR#35498 75 test2<Iter, long double>(); 76 } 77 78 int main() 79 { 80 test<forward_iterator<int*> >(); 81 test<bidirectional_iterator<int*> >(); 82 test<random_access_iterator<int*> >(); 83 test<int*>(); 84 85 #if TEST_STD_VER > 17 86 static_assert(test_constexpr()); 87 #endif 88 } 89
