1 // RUN: %clang_cc1 %s -std=c++20 -fsyntax-only -verify
2 #include "Inputs/std-coroutine.h"
3 
4 namespace std {
5 typedef decltype(sizeof(int)) size_t;
6 }
7 
8 struct Allocator {};
9 
10 struct resumable {
11   struct promise_type {
12     void *operator new(std::size_t sz, Allocator &);
13 
14     resumable get_return_object() { return {}; }
15     auto initial_suspend() { return std::suspend_always(); }
16     auto final_suspend() noexcept { return std::suspend_always(); }
17     void unhandled_exception() {}
18     void return_void(){};
19   };
20 };
21 
22 resumable f1() { // expected-error {{'operator new' provided by 'std::coroutine_traits<resumable>::promise_type' (aka 'resumable::promise_type') is not usable with the function signature of 'f1'}}
23   co_return;
24 }
25 
26 // NOTE: Although the argument here is a rvalue reference and the corresponding
27 // allocation function in resumable::promise_type have lvalue references, it looks
28 // the signature of f2 is invalid. But according to [dcl.fct.def.coroutine]p4:
29 //
30 //   In the following, pi is an lvalue of type Pi, where p1 denotes the object
31 //   parameter and pi+1 denotes the ith non-object function parameter for a
32 //   non-static member function.
33 //
34 // And [dcl.fct.def.coroutine]p9.1
35 //
36 //   overload resolution is performed on a function call created by assembling an argument list.
37 //   The first argument is the amount of space requested, and has type std::size_­t.
38 //   The lvalues p1…pn are the succeeding arguments.
39 //
40 // So the actual type passed to resumable::promise_type::operator new is lvalue
41 // Allocator. It is allowed  to convert a lvalue to a lvalue reference. So the
42 // following one is valid.
43 resumable f2(Allocator &&) {
44   co_return;
45 }
46 
47 resumable f3(Allocator &) {
48   co_return;
49 }
50 
51 resumable f4(Allocator) {
52   co_return;
53 }
54 
55 resumable f5(const Allocator) { // expected-error {{operator new' provided by 'std::coroutine_traits<resumable, const Allocator>::promise_type' (aka 'resumable::promise_type') is not usable}}
56   co_return;
57 }
58 
59 resumable f6(const Allocator &) { // expected-error {{operator new' provided by 'std::coroutine_traits<resumable, const Allocator &>::promise_type' (aka 'resumable::promise_type') is not usable}}
60   co_return;
61 }
62 
63 struct promise_base1 {
64   void *operator new(std::size_t sz); // expected-note {{member found by ambiguous name lookup}}
65 };
66 
67 struct promise_base2 {
68   void *operator new(std::size_t sz); // expected-note {{member found by ambiguous name lookup}}
69 };
70 
71 struct resumable2 {
72   struct promise_type : public promise_base1, public promise_base2 {
73     resumable2 get_return_object() { return {}; }
74     auto initial_suspend() { return std::suspend_always(); }
75     auto final_suspend() noexcept { return std::suspend_always(); }
76     void unhandled_exception() {}
77     void return_void(){};
78   };
79 };
80 
81 resumable2 f7() { // expected-error {{member 'operator new' found in multiple base classes of different types}}
82   co_return;
83 }
84