1 // RUN: %clang_cc1 -fsyntax-only -verify -std=c++11 %s
2 // RUN: %clang_cc1 -fsyntax-only -verify -std=c++1y %s -DCXX1Y
4 struct NonLiteral { NonLiteral(); };
6 // A type is a literal type if it is:
11 // expected-error@-2 {{'void' is not a literal type}}
15 constexpr int f1(double) { return 0; }
19 constexpr int f2(S &) { return 0; }
22 extern BeingDefined beingdefined;
24 static constexpr BeingDefined& t = beingdefined;
27 // - a class type that has all of the following properties:
29 // (implied) - it is complete
31 struct Incomplete; // expected-note 2{{forward declaration of 'Incomplete'}}
32 template<class T> struct ClassTemp {};
34 constexpr Incomplete incomplete = {}; // expected-error {{constexpr variable cannot have non-literal type 'const Incomplete'}} expected-note {{incomplete type 'const Incomplete' is not a literal type}}
35 constexpr Incomplete incomplete2[] = {}; // expected-error {{constexpr variable cannot have non-literal type 'Incomplete const[]'}} expected-note {{incomplete type 'Incomplete const[]' is not a literal type}}
36 constexpr ClassTemp<int> classtemplate = {};
37 constexpr ClassTemp<int> classtemplate2[] = {};
39 // - it has a trivial destructor
41 ~UserProvDtor(); // expected-note {{has a user-provided destructor}}
43 constexpr int f(UserProvDtor) { return 0; } // expected-error {{'UserProvDtor' is not a literal type}}
45 constexpr NonTrivDtor();
46 virtual ~NonTrivDtor() = default; // expected-note {{has a non-trivial destructor}} expected-note {{because it is virtual}}
48 constexpr int f(NonTrivDtor) { return 0; } // expected-error {{'NonTrivDtor' is not a literal type}}
49 struct NonTrivDtorBase {
53 struct DerivedFromNonTrivDtor : T { // expected-note {{'DerivedFromNonTrivDtor<NonTrivDtorBase>' is not literal because it has base class 'NonTrivDtorBase' of non-literal type}}
54 constexpr DerivedFromNonTrivDtor();
56 constexpr int f(DerivedFromNonTrivDtor<NonTrivDtorBase>) { return 0; } // expected-error {{constexpr function's 1st parameter type 'DerivedFromNonTrivDtor<NonTrivDtorBase>' is not a literal type}}
60 constexpr int f(TrivDtor) { return 0; }
61 struct TrivDefaultedDtor {
62 constexpr TrivDefaultedDtor();
63 ~TrivDefaultedDtor() = default;
65 constexpr int f(TrivDefaultedDtor) { return 0; }
67 // - it is an aggregate type or has at least one constexpr constructor or
68 // constexpr constructor template that is not a copy or move constructor
73 constexpr int f3(Agg a) { return a.a; }
75 template<typename T> constexpr CtorTemplate(T);
77 struct CopyCtorOnly { // expected-note {{'CopyCtorOnly' is not literal because it is not an aggregate and has no constexpr constructors other than copy or move constructors}}
78 constexpr CopyCtorOnly(CopyCtorOnly&);
80 constexpr int f(CopyCtorOnly) { return 0; } // expected-error {{'CopyCtorOnly' is not a literal type}}
81 struct MoveCtorOnly { // expected-note {{no constexpr constructors other than copy or move constructors}}
82 constexpr MoveCtorOnly(MoveCtorOnly&&);
84 constexpr int f(MoveCtorOnly) { return 0; } // expected-error {{'MoveCtorOnly' is not a literal type}}
89 constexpr int f(CtorArg<int>) { return 0; } // ok
90 constexpr int f(CtorArg<NonLiteral>) { return 0; } // ok, ctor is still constexpr
91 // We have a special-case diagnostic for classes with virtual base classes.
93 struct HasVBase : virtual VBase {}; // expected-note 2{{virtual base class declared here}}
94 struct Derived : HasVBase {
95 constexpr Derived() {} // expected-error {{constexpr constructor not allowed in struct with virtual base class}}
97 template<typename T> struct DerivedFromVBase : T { // expected-note {{struct with virtual base class is not a literal type}}
98 constexpr DerivedFromVBase();
100 constexpr int f(DerivedFromVBase<HasVBase>) {} // expected-error {{constexpr function's 1st parameter type 'DerivedFromVBase<HasVBase>' is not a literal type}}
101 template<typename T> constexpr DerivedFromVBase<T>::DerivedFromVBase() : T() {}
102 constexpr int nVBase = (DerivedFromVBase<HasVBase>(), 0); // expected-error {{constant expression}} expected-note {{cannot construct object of type 'DerivedFromVBase<HasVBase>' with virtual base class in a constant expression}}
104 // - it has all non-static data members and base classes of literal types
105 struct NonLitMember {
106 S s; // expected-note {{has data member 's' of non-literal type 'S'}}
108 constexpr int f(NonLitMember) {} // expected-error {{1st parameter type 'NonLitMember' is not a literal type}}
110 S { // expected-note {{base class 'S' of non-literal type}}
111 constexpr NonLitBase();
113 constexpr int f(NonLitBase) { return 0; } // expected-error {{'NonLitBase' is not a literal type}}
114 struct LitMemBase : Agg {
119 T t; // expected-note {{'MemberType<NonLiteral>' is not literal because it has data member 't' of non-literal type 'NonLiteral'}}
120 constexpr MemberType();
122 constexpr int f(MemberType<int>) { return 0; }
123 constexpr int f(MemberType<NonLiteral>) { return 0; } // expected-error {{not a literal type}}
125 // - an array of literal type [C++1y] other than an array of runtime bound
130 TrivDefaultedDtor tdd[3];
132 constexpr int f(ArrGood) { return 0; }
135 S s[3]; // expected-note {{data member 's' of non-literal type 'S [3]'}}
137 constexpr int f(ArrBad) { return 0; } // expected-error {{1st parameter type 'ArrBad' is not a literal type}}
139 constexpr int arb(int n) {
140 int a[n]; // expected-error {{variable of non-literal type 'int [n]' cannot be defined in a constexpr function}}
142 constexpr long Overflow[ // expected-error {{constexpr variable cannot have non-literal type 'long const[(1 << 30) << 2]'}}
143 (1 << 30) << 2]{}; // expected-warning {{requires 34 bits to represent}}