clang/test/CXX/dcl.decl/dcl.meaning/p1-0x.cpp

   1 // RUN: %clang_cc1 -fsyntax-only -verify -std=c++11 %s
   2
   3 // The nested-name-specifier of a qualified declarator-id shall not begin with a decltype-specifier.
   4 class foo {
   5   static int i;
   6   void func();
   7 };
   8
   9 int decltype(foo())::i; // expected-error{{'decltype' cannot be used to name a declaration}}
  10 void decltype(foo())::func() { // expected-error{{'decltype' cannot be used to name a declaration}}
  11 }
  12
  13
  14 template<typename T>
  15 class tfoo {
  16   static int i;
  17   void func();
  18 };
  19
  20 template<typename T>
  21 int decltype(tfoo<T>())::i; // expected-error{{nested name specifier 'decltype(tfoo<T>())::' for declaration does not refer into a class, class template or class template partial specialization}}
  22 template<typename T>
  23 void decltype(tfoo<T>())::func() { // expected-error{{nested name specifier 'decltype(tfoo<T>())::' for declaration does not refer into a class, class template or class template partial specialization}}
  24 }
  25
  26 // An init-declarator named with a qualified-id can refer to an element of the
  27 // inline namespace set of the named namespace.
  28 namespace inline_namespaces {
  29   namespace N {
  30     inline namespace M {
  31       void f(); // expected-note {{possible target}}
  32       void g();
  33       extern int m; // expected-note {{candidate}}
  34       extern int n;
  35       struct S; // expected-note {{candidate}}
  36       struct T;
  37       enum E : int; // expected-note {{candidate}}
  38       enum F : int;
  39       template<typename T> void ft(); // expected-note {{here}}
  40       template<typename T> void gt(); // expected-note {{here}}
  41       template<typename T> extern int mt; // expected-note {{here}} expected-warning {{extension}}
  42       template<typename T> extern int nt; // expected-note {{here}} expected-warning {{extension}}
  43       template<typename T> struct U; // expected-note {{here}}
  44       template<typename T> struct V; // expected-note {{here}}
  45     }
  46
  47     // When named by unqualified-id, we do *not* look in the inline namespace
  48     // set.
  49     void f() {} // expected-note {{possible target}}
  50     int m; // expected-note {{candidate}}
  51     struct S {}; // expected-note {{candidate}}
  52     enum E : int {}; // expected-note {{candidate}}
  53
  54     static_assert(&f != &M::f, ""); // expected-error {{reference to overloaded function could not be resolved}}
  55     static_assert(&m != &M::m, ""); // expected-error {{ambiguous}}
  56     typedef S X; // expected-error {{ambiguous}}
  57     typedef E Y; // expected-error {{ambiguous}}
  58
  59     // When named by (unqualified) template-id, we do look in the inline
  60     // namespace set.  See [namespace.def]p8, [temp.explicit]p3,
  61     // [temp.expl.spec]p2.
  62     //
  63     // This is not explicitly specified for partial specializations, but
  64     // that is just a language defect.
  65     template<> void ft<int>() {}
  66     template void ft<char>(); // expected-error {{undefined}}
  67
  68     template<typename T> int mt<T*>;
  69     template<> int mt<int>;
  70     template int mt<int*>;
  71     template int mt<char>; // expected-error {{undefined}}
  72
  73     template<typename T> struct U<T*> {};
  74     template<> struct U<int> {};
  75     template struct U<int*>;
  76     template struct U<char>; // expected-error {{undefined}}
  77   }
  78
  79   // When named by qualified-id, we *do* look in the inline namespace set.
  80   void N::g() {}
  81   int N::n;
  82   struct N::T {};
  83   enum N::F : int {};
  84
  85   static_assert(&N::g == &N::M::g, "");
  86   static_assert(&N::n == &N::M::n, "");
  87   typedef N::T X;
  88   typedef N::M::T X;
  89   typedef N::F Y;
  90   typedef N::M::F Y;
  91
  92   template<> void N::gt<int>() {}
  93   template void N::gt<char>(); // expected-error {{undefined}}
  94
  95   template<typename T> int N::nt<T*>;
  96   template<> int N::nt<int>;
  97   template int N::nt<int*>;
  98   template int N::nt<char>; // expected-error {{undefined}}
  99
 100   template<typename T> struct N::V<T*> {};
 101   template<> struct N::V<int> {};
 102   template struct N::V<int*>;
 103   template struct N::V<char>; // expected-error {{undefined}}
 104
 105   struct Q {};
 106
 107   // Perversely, inline anonymous namespaces can cause an ostensibly
 108   // external-linkage declaration to acquire internal linkage when
 109   // redeclared with a qualified name.
 110   inline namespace {
 111     struct Q {} q;
 112     int f_in_inline();
 113     extern int v_in_inline;
 114     typedef int t_in_inline;
 115   }
 116   // FIXME: These "extra qualification" warnings are bogus: the qualification
 117   // changes the meaning of the program.
 118   int inline_namespaces::f_in_inline() { // expected-warning {{extra qualification}}
 119     // Finds <anon>::Q, not inline_namespaces::Q
 120     Q x = q;
 121     return 0;
 122   }
 123   int inline_namespaces::v_in_inline = // expected-warning {{extra qualification}}
 124     (Q(q), 0);
 125 }