1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
| // RUN: %clang_cc1 -std=c++11 -fsyntax-only -verify %s
// This is a collection of various template metafunctions involving
// variadic templates, which are meant to exercise common use cases.
template<typename T, typename U>
struct is_same {
static const bool value = false;
};
template<typename T>
struct is_same<T, T> {
static const bool value = true;
};
template<typename...> struct tuple { };
template<int ...> struct int_tuple { };
template<typename T, typename U> struct pair { };
namespace Count {
template<typename Head, typename ...Tail>
struct count {
static const unsigned value = 1 + count<Tail...>::value;
};
template<typename T>
struct count<T> {
static const unsigned value = 1;
};
int check1[count<int>::value == 1? 1 : -1];
int check2[count<float, double>::value == 2? 1 : -1];
int check3[count<char, signed char, unsigned char>::value == 3? 1 : -1];
}
namespace CountWithPackExpansion {
template<typename ...> struct count;
template<typename Head, typename ...Tail>
struct count<Head, Tail...> {
static const unsigned value = 1 + count<Tail...>::value;
};
template<>
struct count<> {
static const unsigned value = 0;
};
int check0[count<>::value == 0? 1 : -1];
int check1[count<int>::value == 1? 1 : -1];
int check2[count<float, double>::value == 2? 1 : -1];
int check3[count<char, signed char, unsigned char>::value == 3? 1 : -1];
}
namespace Replace {
// Simple metafunction that replaces the template arguments of
// template template parameters with 'int'.
template<typename T>
struct EverythingToInt;
template<template<typename ...> class TT, typename T1, typename T2>
struct EverythingToInt<TT<T1, T2> > {
typedef TT<int, int> type;
};
int check0[is_same<EverythingToInt<tuple<double, float>>::type,
tuple<int, int>>::value? 1 : -1];
}
namespace Math {
template<int ...Values>
struct double_values {
typedef int_tuple<Values*2 ...> type;
};
int check0[is_same<double_values<1, 2, -3>::type,
int_tuple<2, 4, -6>>::value? 1 : -1];
template<int ...Values>
struct square {
typedef int_tuple<(Values*Values)...> type;
};
int check1[is_same<square<1, 2, -3>::type,
int_tuple<1, 4, 9>>::value? 1 : -1];
template<typename IntTuple> struct square_tuple;
template<int ...Values>
struct square_tuple<int_tuple<Values...>> {
typedef int_tuple<(Values*Values)...> type;
};
int check2[is_same<square_tuple<int_tuple<1, 2, -3> >::type,
int_tuple<1, 4, 9>>::value? 1 : -1];
template<int ...Values> struct sum;
template<int First, int ...Rest>
struct sum<First, Rest...> {
static const int value = First + sum<Rest...>::value;
};
template<>
struct sum<> {
static const int value = 0;
};
int check3[sum<1, 2, 3, 4, 5>::value == 15? 1 : -1];
template<int ... Values>
struct lazy_sum {
int operator()() {
return sum<Values...>::value;
}
};
void f() {
lazy_sum<1, 2, 3, 4, 5>()();
}
}
namespace ListMath {
template<typename T, T ... V> struct add;
template<typename T, T i, T ... V>
struct add<T, i, V...> {
static const T value = i + add<T, V...>::value;
};
template<typename T>
struct add<T> {
static const T value = T();
};
template<typename T, T ... V>
struct List {
struct sum {
static const T value = add<T, V...>::value;
};
};
template<int ... V>
struct ListI : public List<int, V...> {
};
int check0[ListI<1, 2, 3>::sum::value == 6? 1 : -1];
}
namespace Indices {
template<unsigned I, unsigned N, typename IntTuple>
struct build_indices_impl;
template<unsigned I, unsigned N, int ...Indices>
struct build_indices_impl<I, N, int_tuple<Indices...> >
: build_indices_impl<I+1, N, int_tuple<Indices..., I> > {
};
template<unsigned N, int ...Indices>
struct build_indices_impl<N, N, int_tuple<Indices...> > {
typedef int_tuple<Indices...> type;
};
template<unsigned N>
struct build_indices : build_indices_impl<0, N, int_tuple<> > { };
int check0[is_same<build_indices<5>::type,
int_tuple<0, 1, 2, 3, 4>>::value? 1 : -1];
}
namespace TemplateTemplateApply {
template<typename T, template<class> class ...Meta>
struct apply_each {
typedef tuple<typename Meta<T>::type...> type;
};
template<typename T>
struct add_reference {
typedef T& type;
};
template<typename T>
struct add_pointer {
typedef T* type;
};
template<typename T>
struct add_const {
typedef const T type;
};
int check0[is_same<apply_each<int,
add_reference, add_pointer, add_const>::type,
tuple<int&, int*, int const>>::value? 1 : -1];
template<typename T, template<class> class ...Meta>
struct apply_each_indirect {
typedef typename apply_each<T, Meta...>::type type;
};
int check1[is_same<apply_each_indirect<int, add_reference, add_pointer,
add_const>::type,
tuple<int&, int*, int const>>::value? 1 : -1];
template<typename T, typename ...Meta>
struct apply_each_nested {
typedef typename apply_each<T, Meta::template apply...>::type type;
};
struct add_reference_meta {
template<typename T>
struct apply {
typedef T& type;
};
};
struct add_pointer_meta {
template<typename T>
struct apply {
typedef T* type;
};
};
struct add_const_meta {
template<typename T>
struct apply {
typedef const T type;
};
};
int check2[is_same<apply_each_nested<int, add_reference_meta,
add_pointer_meta, add_const_meta>::type,
tuple<int&, int*, int const>>::value? 1 : -1];
}
namespace FunctionTypes {
template<typename FunctionType>
struct Arity;
template<typename R, typename ...Types>
struct Arity<R(Types...)> {
static const unsigned value = sizeof...(Types);
};
template<typename R, typename ...Types>
struct Arity<R(Types......)> { // expected-warning {{varargs}} expected-note {{pack}} expected-note {{insert ','}}
static const unsigned value = sizeof...(Types);
};
template<typename R, typename T1, typename T2, typename T3, typename T4>
struct Arity<R(T1, T2, T3, T4)>; // expected-note{{template is declared here}}
int check0[Arity<int()>::value == 0? 1 : -1];
int check1[Arity<int(float, double)>::value == 2? 1 : -1];
int check2[Arity<int(float...)>::value == 1? 1 : -1];
int check3[Arity<int(float, double, long double...)>::value == 3? 1 : -1];
Arity<int(float, double, long double, char)> check4; // expected-error{{implicit instantiation of undefined template 'FunctionTypes::Arity<int (float, double, long double, char)>'}}
}
namespace SuperReplace {
template<typename T>
struct replace_with_int {
typedef int type;
};
template<template<typename ...> class TT, typename ...Types>
struct replace_with_int<TT<Types...>> {
typedef TT<typename replace_with_int<Types>::type...> type;
};
int check0[is_same<replace_with_int<pair<tuple<float, double, short>,
pair<char, unsigned char>>>::type,
pair<tuple<int, int, int>, pair<int, int>>>::value? 1 : -1];
}
|