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1 // PR c++/56970
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2 // { dg-do compile { target c++11 } }
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3
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4 template <typename T>
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5 struct has
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6 {
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7 template <typename>
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8 constexpr static int test(...) {
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9 return 0;
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10 }
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11
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12 template <typename C>
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13 constexpr static int test(decltype(sizeof(C::x))) { // Doesn't compile.
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14 return 1; // Is a member variable.
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15 }
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16
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17 template <typename C, int c = sizeof(decltype(((C*)nullptr)->x()))>
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18 constexpr static int test(int) {
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19 return 2; // Is a member function.
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20 }
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21
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22 static const int value = test<T>(0);
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23 };
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24
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25 struct foo {
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26 int x;
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27 };
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28
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29 struct bar {
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30 int x();
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31 };
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32
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33 static_assert(has<int>::value == 0, "");
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34 static_assert(has<foo>::value == 1, "");
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35 static_assert(has<bar>::value == 2, "");
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