clang/test/SemaCXX/specialization-diagnose-crash.cpp

   1 // RUN: %clang_cc1 -fsyntax-only %s --std=c++17 -verify
   2 // This is a reduction of GH57370 and GH58028, originally appearing
   3 // in libstdc++'s variant code.
   4
   5 struct V1 {};
   6 struct V2 : V1 {
   7   int &a;
   8 };
   9
  10 template <class T> using void_t = void;
  11
  12 template <class T> struct X { T x; };
  13
  14 template <class T1, class T2, class = void> struct Variant {
  15   Variant() = delete; // expected-note {{deleted here}}
  16 };
  17
  18 template <class T1, class T2>
  19 struct Variant<T1, T2, void_t<decltype(X<T2>{T1()})>> {};
  20
  21 void f() {
  22   Variant<V1, V1>();
  23   Variant<V1, V2>(); // expected-error {{call to deleted constructor}}
  24 }