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145
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1 // { dg-do compile { target c++2a } }
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2
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3 template<typename T>
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4 concept True = true;
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5
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6 template<typename T>
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7 concept False = false;
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8
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9 template<typename T>
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10 concept Int = __is_same_as(T, int);
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11
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12 static_assert(True<int>);
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13 static_assert(!False<int>);
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14 static_assert(False<int>); // { dg-error "static assertion failed" }
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15
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16 constexpr bool will_be_true() {
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17 if (True<int>)
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18 return true;
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19 return false;
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20 }
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21
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22 constexpr bool will_be_false() {
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23 if (!False<int>)
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24 return true;
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25 return false;
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26 }
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27
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28 static_assert(will_be_true());
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29 static_assert(will_be_false());
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30
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31 template<typename T>
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32 constexpr bool is_int() {
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33 if (Int<T>)
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34 return true;
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35 return false;
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36 }
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37
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38 static_assert(is_int<int>());
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39 static_assert(is_int<void>()); // { dg-error "static assertion failed" }
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40
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41 template<typename T>
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42 constexpr bool f1() {
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43 if (Int<int>) // Note: always true.
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44 return true;
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45 return false;
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46 }
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47 static_assert(f1<int>());
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48 static_assert(f1<void>());
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49
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50
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51 template<typename T>
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52 constexpr bool f2() {
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53 if constexpr (Int<int>) // Note: always true.
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54 return true;
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55 return false;
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56 }
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57 static_assert(f2<int>());
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58 static_assert(f2<void>());
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59
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60 template<typename T>
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61 concept C = true;
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62
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63 int driver() {
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64 bool c_int = (C<int>);
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65 if((C<int>))
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66 ;
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67 return c_int;
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68 }
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69
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