clang/test/CXX/temp/temp.constr/temp.constr.decl/p3.cpp

   1 // RUN: %clang_cc1 -std=c++2a -x c++ -verify %s
   2
   3 template<typename T>
   4 struct X {
   5     using Y = typename T::invalid;
   6 };
   7
   8 template<typename T>
   9 concept Invalid = X<T>{};
  10
  11 template<typename T>
  12 concept False = false; // expected-note{{because 'false' evaluated to false}}
  13
  14 template<typename T>
  15 concept True = true;
  16
  17 // TODO: Concepts: Uncomment trailing requires clauses here when we have correct substitution.
  18 //template<True T>
  19 //  requires False<T>
  20 //void g1() requires Invalid<T>;
  21 //
  22 //using g1i = decltype(g1<int>());
  23
  24 template<False T> // expected-note{{because 'int' does not satisfy 'False'}}
  25   requires Invalid<T>
  26 void g2(); // requires Invalid<T>;
  27 // expected-note@-1{{candidate template ignored: constraints not satisfied [with T = int]}}
  28
  29 using g2i = decltype(g2<int>());
  30 // expected-error@-1{{no matching function for call to 'g2'}}