clang/test/SemaCXX/literal-type.cpp

   1 // RUN: %clang_cc1 -fsyntax-only -verify -std=c++11 %s
   2
   3 static_assert(__is_literal(int), "fail");
   4 static_assert(__is_literal_type(int), "fail"); // alternate spelling for GCC
   5 static_assert(__is_literal(void*), "fail");
   6 enum E { E1 };
   7 static_assert(__is_literal(E), "fail");
   8 static_assert(__is_literal(decltype(E1)), "fail");
   9 typedef int IAR[10];
  10 static_assert(__is_literal(IAR), "fail");
  11 typedef int Vector __attribute__((vector_size(16)));
  12 typedef int VectorExt __attribute__((ext_vector_type(4)));
  13 static_assert(__is_literal(Vector), "fail");
  14 static_assert(__is_literal(VectorExt), "fail");
  15
  16 // C++0x [basic.types]p10:
  17 //   A type is a literal type if it is:
  18 //    [...]
  19 //    -- a class type that has all of the following properties:
  20 //        -- it has a trivial destructor
  21 //        -- every constructor call and full-expression in the
  22 //           brace-or-equal-initializers for non-static data members (if an) is
  23 //           a constant expression,
  24 //        -- it is an aggregate type or has at least one constexpr constructor
  25 //           or constructor template that is not a copy or move constructor, and
  26 //           [DR1452 adds class types with trivial default constructors to
  27 //            this list]
  28 //        -- it has all non-static data members and base classes of literal
  29 //           types
  30 struct Empty {};
  31 struct LiteralType {
  32   int x;
  33   E e;
  34   IAR arr;
  35   Empty empty;
  36   int method();
  37 };
  38 struct HasDtor { ~HasDtor(); };
  39
  40 class NonAggregate { int x; };
  41 struct NonLiteral { NonLiteral(); };
  42 struct HasNonLiteralBase : NonLiteral {};
  43 struct HasNonLiteralMember { HasDtor x; };
  44
  45 static_assert(__is_literal(Empty), "fail");
  46 static_assert(__is_literal(LiteralType), "fail");
  47 static_assert(__is_literal(NonAggregate), "fail");
  48 static_assert(!__is_literal(NonLiteral), "fail");
  49 static_assert(!__is_literal(HasDtor), "fail");
  50 static_assert(!__is_literal(HasNonLiteralBase), "fail");
  51 static_assert(!__is_literal(HasNonLiteralMember), "fail");
  52
  53 // DR1361 removes the brace-or-equal-initializer bullet so that we can allow:
  54 extern int f(); // expected-note {{here}}
  55 struct HasNonConstExprMemInit {
  56   int x = f(); // expected-note {{non-constexpr function}}
  57   constexpr HasNonConstExprMemInit() {} // expected-error {{never produces a constant expression}}
  58   constexpr HasNonConstExprMemInit(int y) : x(y) {} // ok
  59 };
  60 static_assert(__is_literal(HasNonConstExprMemInit), "fail");
  61
  62 class HasConstExprCtor {
  63   int x;
  64 public:
  65   constexpr HasConstExprCtor(int x) : x(x) {}
  66 };
  67 template <typename T> class HasConstExprCtorTemplate {
  68   T x;
  69 public:
  70   template <typename U> constexpr HasConstExprCtorTemplate(U y) : x(y) {}
  71 };
  72 template <typename T> class HasConstExprCtorT {
  73   constexpr HasConstExprCtorT(T) {}
  74 };
  75 static_assert(__is_literal(HasConstExprCtor), "fail");
  76 static_assert(__is_literal(HasConstExprCtorTemplate<int>), "fail");
  77 static_assert(__is_literal(HasConstExprCtorT<NonLiteral>), "fail");