clang/test/SemaCXX/concept-crash-on-diagnostic.cpp

   1 // RUN: %clang_cc1 -fsyntax-only -std=c++20 -verify %s
   2
   3 template <typename Iterator> class normal_iterator {};
   4
   5 template <typename From, typename To> struct is_convertible {};
   6
   7 template <typename From, typename To>
   8 inline constexpr bool is_convertible_v = is_convertible<From, To>::value; // expected-error {{no member named 'value' in 'is_convertible<bool, bool>'}}
   9
  10 template <typename From, typename To>
  11 concept convertible_to = is_convertible_v<From, To>; // #1
  12
  13 template <typename IteratorL, typename IteratorR>
  14   requires requires(IteratorL lhs, IteratorR rhs) { // #2
  15     { lhs == rhs } -> convertible_to<bool>; // #3
  16   }
  17 constexpr bool compare(normal_iterator<IteratorL> lhs, normal_iterator<IteratorR> rhs) { // #4
  18   return false;
  19 }
  20
  21 class Object;
  22
  23 void function() {
  24   normal_iterator<Object *> begin, end;
  25   compare(begin, end); // expected-error {{no matching function for call to 'compare'}} #5
  26 }
  27
  28 // expected-note@#1 {{in instantiation of variable template specialization 'is_convertible_v<bool, bool>' requested here}}
  29 // expected-note@#1 {{substituting template arguments into constraint expression here}}
  30 // expected-note@#3 {{checking the satisfaction of concept 'convertible_to<bool, bool>'}}
  31 // expected-note@#2 {{substituting template arguments into constraint expression here}}
  32 // expected-note@#5 {{checking constraint satisfaction for template 'compare<Object *, Object *>'}}
  33 // expected-note@#5 {{in instantiation of function template specialization 'compare<Object *, Object *>' requested here}}
  34
  35 // expected-note@#4 {{candidate template ignored: constraints not satisfied [with IteratorL = Object *, IteratorR = Object *]}}
  36 // We don't know exactly the substituted type for `lhs == rhs`, thus a placeholder 'expr-type' is emitted.
  37 // expected-note@#3 {{because 'convertible_to<expr-type, bool>' would be invalid}}