p3-1y.cpp revision a2c3646c35dd09d21b74826240aa916545b1873f
1a2c3646c35dd09d21b74826240aa916545b1873fRichard Smith// RUN: %clang_cc1 -fsyntax-only -verify %s -std=c++1y
2a2c3646c35dd09d21b74826240aa916545b1873fRichard Smith// RUN: %clang_cc1 -fsyntax-only -verify %s -std=c++11 -Wno-c++1y-extensions
3a2c3646c35dd09d21b74826240aa916545b1873fRichard Smith
4a2c3646c35dd09d21b74826240aa916545b1873fRichard Smith// FIXME: This is in p11 (?) in C++1y.
5a2c3646c35dd09d21b74826240aa916545b1873fRichard Smithvoid f() {
6a2c3646c35dd09d21b74826240aa916545b1873fRichard Smith  decltype(auto) a = a; // expected-error{{variable 'a' declared with 'auto' type cannot appear in its own initializer}}
7a2c3646c35dd09d21b74826240aa916545b1873fRichard Smith  if (decltype(auto) b = b) {} // expected-error {{variable 'b' declared with 'auto' type cannot appear in its own initializer}}
8a2c3646c35dd09d21b74826240aa916545b1873fRichard Smith  decltype(auto) c = ({ decltype(auto) d = c; 0; }); // expected-error {{variable 'c' declared with 'auto' type cannot appear in its own initializer}}
9a2c3646c35dd09d21b74826240aa916545b1873fRichard Smith}
10a2c3646c35dd09d21b74826240aa916545b1873fRichard Smith
11a2c3646c35dd09d21b74826240aa916545b1873fRichard Smithvoid g() {
12a2c3646c35dd09d21b74826240aa916545b1873fRichard Smith  decltype(auto) a; // expected-error{{declaration of variable 'a' with type 'decltype(auto)' requires an initializer}}
13a2c3646c35dd09d21b74826240aa916545b1873fRichard Smith
14a2c3646c35dd09d21b74826240aa916545b1873fRichard Smith  decltype(auto) *b; // expected-error{{cannot form pointer to 'decltype(auto)'}} expected-error{{declaration of variable 'b' with type 'decltype(auto) *' requires an initializer}}
15a2c3646c35dd09d21b74826240aa916545b1873fRichard Smith
16a2c3646c35dd09d21b74826240aa916545b1873fRichard Smith  if (decltype(auto) b) {} // expected-error {{must have an initializer}}
17a2c3646c35dd09d21b74826240aa916545b1873fRichard Smith  for (;decltype(auto) b;) {} // expected-error {{must have an initializer}}
18a2c3646c35dd09d21b74826240aa916545b1873fRichard Smith  while (decltype(auto) b) {} // expected-error {{must have an initializer}}
19a2c3646c35dd09d21b74826240aa916545b1873fRichard Smith  if (decltype(auto) b = true) { (void)b; }
20a2c3646c35dd09d21b74826240aa916545b1873fRichard Smith}
21a2c3646c35dd09d21b74826240aa916545b1873fRichard Smith
22a2c3646c35dd09d21b74826240aa916545b1873fRichard Smithdecltype(auto) n(1,2,3); // expected-error{{initializer for variable 'n' with type 'decltype(auto)' contains multiple expressions}}
23a2c3646c35dd09d21b74826240aa916545b1873fRichard Smith
24a2c3646c35dd09d21b74826240aa916545b1873fRichard Smithnamespace N
25a2c3646c35dd09d21b74826240aa916545b1873fRichard Smith{
26a2c3646c35dd09d21b74826240aa916545b1873fRichard Smith  // All of these are references, because a string literal is an lvalue.
27a2c3646c35dd09d21b74826240aa916545b1873fRichard Smith  decltype(auto) a = "const char (&)[19]", b = a, c = (a);
28a2c3646c35dd09d21b74826240aa916545b1873fRichard Smith}
29a2c3646c35dd09d21b74826240aa916545b1873fRichard Smith
30a2c3646c35dd09d21b74826240aa916545b1873fRichard Smithvoid h() {
31a2c3646c35dd09d21b74826240aa916545b1873fRichard Smith  decltype(auto) b = 42ULL;
32a2c3646c35dd09d21b74826240aa916545b1873fRichard Smith
33a2c3646c35dd09d21b74826240aa916545b1873fRichard Smith  for (decltype(auto) c = 0; c < b; ++c) {
34a2c3646c35dd09d21b74826240aa916545b1873fRichard Smith  }
35a2c3646c35dd09d21b74826240aa916545b1873fRichard Smith}
36a2c3646c35dd09d21b74826240aa916545b1873fRichard Smith
37a2c3646c35dd09d21b74826240aa916545b1873fRichard Smithtemplate<typename T, typename U> struct same;
38a2c3646c35dd09d21b74826240aa916545b1873fRichard Smithtemplate<typename T> struct same<T, T> {};
39a2c3646c35dd09d21b74826240aa916545b1873fRichard Smith
40a2c3646c35dd09d21b74826240aa916545b1873fRichard Smithvoid i() {
41a2c3646c35dd09d21b74826240aa916545b1873fRichard Smith  decltype(auto) x = 5;
42a2c3646c35dd09d21b74826240aa916545b1873fRichard Smith  decltype(auto) int r; // expected-error {{cannot combine with previous 'decltype(auto)' declaration specifier}} expected-error {{requires an initializer}}
43a2c3646c35dd09d21b74826240aa916545b1873fRichard Smith}
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