clang/test/CXX/conv/conv.fctptr/p1.cpp

   1 // RUN: %clang_cc1 -std=c++1z -verify %s -triple x86_64-unknown-unknown
   2
   3 struct S;
   4
   5 typedef void Nothrow() noexcept;
   6 typedef void Throw();
   7
   8 Nothrow *a;
   9 Throw *b;
  10 Nothrow S::*c;
  11 Throw S::*d;
  12
  13 void test() {
  14   a = b; // expected-error {{incompatible function pointer types assigning to 'Nothrow *' (aka 'void (*)() noexcept') from 'Throw *' (aka 'void (*)()')}}
  15   b = a;
  16   c = d; // expected-error {{assigning to 'Nothrow S::*' from incompatible type 'Throw S::*': different exception specifications}}
  17   d = c;
  18
  19   // Function pointer conversions do not combine properly with qualification conversions.
  20   // FIXME: This seems like a defect.
  21   Nothrow *const *pa = b; // expected-error {{cannot initialize}}
  22   Throw *const *pb = a; // expected-error {{cannot initialize}}
  23   Nothrow *const S::*pc = d; // expected-error {{cannot initialize}}
  24   Throw *const S::*pd = c; // expected-error {{cannot initialize}}
  25 }
  26
  27 // ... The result is a pointer to the function.
  28 void f() noexcept;
  29 constexpr void (*p)() = &f;
  30 static_assert(f == p);
  31
  32 struct S { void f() noexcept; };
  33 constexpr void (S::*q)() = &S::f;
  34 static_assert(q == &S::f);
  35
  36
  37 namespace std_example {
  38   void (*p)();
  39   void (**pp)() noexcept = &p; // expected-error {{cannot initialize a variable of type 'void (**)() noexcept' with an rvalue of type 'void (**)()'}}
  40
  41   struct S { typedef void (*p)(); operator p(); }; // expected-note {{candidate}}
  42   void (*q)() noexcept = S(); // expected-error {{no viable conversion from 'S' to 'void (*)() noexcept'}}
  43 }