clang/test/SemaCXX/cxx2b-deducing-this-coro.cpp

   1 // RUN: %clang_cc1 -std=c++2b %s -fsyntax-only -verify
   2
   3 #include "Inputs/std-coroutine.h"
   4
   5 struct S;
   6 template <typename T>
   7 class coro_test {
   8 public:
   9     struct promise_type;
  10     using handle = std::coroutine_handle<promise_type>;
  11         struct promise_type {
  12         promise_type(const promise_type&) = delete; // #copy-ctr
  13         promise_type(T);  // #candidate
  14         coro_test get_return_object();
  15         std::suspend_never initial_suspend();
  16             std::suspend_never final_suspend() noexcept;
  17             void return_void();
  18         void unhandled_exception();
  19
  20
  21         template<typename Arg, typename... Args>
  22         void* operator new(decltype(0zu) sz, Arg&&, Args&... args) {
  23             static_assert(!__is_same(__decay(Arg), S), "Ok"); // expected-error 2{{Ok}}
  24         }
  25
  26     };
  27 private:
  28         handle h;
  29 };
  30
  31
  32 template <typename Ret, typename... P>
  33 struct std::coroutine_traits<coro_test<S&>, Ret, P...> {
  34   using promise_type = coro_test<S&>::promise_type;
  35   static_assert(!__is_same(Ret, S&), "Ok"); // expected-error{{static assertion failed due to requirement '!__is_same(S &, S &)': Ok}}
  36 };
  37
  38
  39 struct S {
  40
  41     coro_test<S&> ok(this S&, int) {
  42         co_return; // expected-note {{in instantiation}}
  43     }
  44
  45     coro_test<const S&> ok2(this const S&) { // expected-note {{in instantiation}}
  46         co_return;
  47     }
  48
  49     coro_test<int> ko(this const S&) {  // expected-error {{no matching constructor for initialization of 'std::coroutine_traits<coro_test<int>, const S &>::promise_type'}} \
  50                                         // expected-note {{in instantiation}} \
  51                                        // FIXME: the message below is unhelpful but this is pre-existing
  52                                        // expected-note@#candidate {{candidate constructor not viable: requires 1 argument, but 0 were provided}} \
  53                                        // expected-note@#copy-ctr  {{candidate constructor not viable}}
  54         co_return;
  55     }
  56
  57 };