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 {
operator ()gen_test32 TEST_CONSTEXPR int operator()() const {return 2;}
33 };
34
35
36 #if TEST_STD_VER > 17
test_constexpr()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
test2()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
test()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
main()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