179 lines · cpp
1// RUN: %clang_cc1 -fsyntax-only -verify -std=c++11 %s2// RUN: %clang_cc1 -fsyntax-only -verify -std=c++20 %s3 4 5static_assert(__is_literal(int), "fail");6static_assert(__is_literal_type(int), "fail"); // alternate spelling for GCC7static_assert(__is_literal(void*), "fail");8enum E { E1 };9static_assert(__is_literal(E), "fail");10static_assert(__is_literal(decltype(E1)), "fail");11typedef int IAR[10];12static_assert(__is_literal(IAR), "fail");13typedef int Vector __attribute__((vector_size(16)));14typedef int VectorExt __attribute__((ext_vector_type(4)));15static_assert(__is_literal(Vector), "fail");16static_assert(__is_literal(VectorExt), "fail");17 18// C++0x [basic.types]p10:19// A type is a literal type if it is:20// [...]21// -- a class type that has all of the following properties:22// -- it has a trivial destructor23// [P0784R7 changed the condition to "constexpr destructor" in C++20]24// -- every constructor call and full-expression in the25// brace-or-equal-initializers for non-static data members (if an) is26// a constant expression,27// -- it is an aggregate type or has at least one constexpr constructor28// or constructor template that is not a copy or move constructor, and29// [DR1452 adds class types with trivial default constructors to30// this list]31// -- it has all non-static data members and base classes of literal32// types33struct Empty {};34struct LiteralType {35 int x;36 E e;37 IAR arr;38 Empty empty;39 int method();40};41struct HasDtor { ~HasDtor(); };42 43class NonAggregate { int x; };44struct NonLiteral { NonLiteral(); };45struct HasNonLiteralBase : NonLiteral {};46struct HasNonLiteralMember { HasDtor x; };47 48static_assert(__is_literal(Empty), "fail");49static_assert(__is_literal(LiteralType), "fail");50static_assert(__is_literal(NonAggregate), "fail");51static_assert(!__is_literal(NonLiteral), "fail");52static_assert(!__is_literal(HasDtor), "fail");53static_assert(!__is_literal(HasNonLiteralBase), "fail");54static_assert(!__is_literal(HasNonLiteralMember), "fail");55 56// DR1361 removes the brace-or-equal-initializer bullet so that we can allow:57extern int f(); // expected-note {{here}}58struct HasNonConstExprMemInit {59 int x = f(); // expected-note {{non-constexpr function}}60 constexpr HasNonConstExprMemInit() {} // expected-error {{never produces a constant expression}}61 constexpr HasNonConstExprMemInit(int y) : x(y) {} // ok62};63static_assert(__is_literal(HasNonConstExprMemInit), "fail");64 65class HasConstExprCtor {66 int x;67public:68 constexpr HasConstExprCtor(int x) : x(x) {}69};70template <typename T> class HasConstExprCtorTemplate {71 T x;72public:73 template <typename U> constexpr HasConstExprCtorTemplate(U y) : x(y) {}74};75template <typename T> class HasConstExprCtorT {76 constexpr HasConstExprCtorT(T) {}77};78static_assert(__is_literal(HasConstExprCtor), "fail");79static_assert(__is_literal(HasConstExprCtorTemplate<int>), "fail");80static_assert(__is_literal(HasConstExprCtorT<NonLiteral>), "fail");81 82 83#if __cplusplus >= 202003L84namespace GH77924 {85 86struct A { A(); };87template <class T>88struct opt {89 union Data {90 constexpr Data() : x{} {}91 constexpr ~Data() {}92 char x;93 T data;94 };95 96 constexpr opt() : data{} {}97 constexpr ~opt() { if (engaged) data.data.~T(); }98 Data data;99 bool engaged = false;100};101 102consteval void foo() {103 opt<A> a;104}105 106void test() {107 foo();108}109 110}111#endif112 113#if __cplusplus >= 201103L114namespace GH85550 {115struct HasDefaultCtorAndNonConstexprDtor {116 constexpr HasDefaultCtorAndNonConstexprDtor() = default;117 ~HasDefaultCtorAndNonConstexprDtor() {}118};119 120union UnionWithNonLiteralMember {121 HasDefaultCtorAndNonConstexprDtor x;122 int y;123 124 constexpr UnionWithNonLiteralMember() : x{} {}125};126#if __cplusplus >= 202002L127static_assert(__is_literal(UnionWithNonLiteralMember), "fail");128#else129static_assert(!__is_literal(UnionWithNonLiteralMember), "fail");130#endif131 132union UnionWithNonLiteralMemberExplicitDtor1 {133 HasDefaultCtorAndNonConstexprDtor x;134 int y;135 // expected-note@-2 {{destructor of 'UnionWithNonLiteralMemberExplicitDtor1' is implicitly deleted because variant field 'x' has a non-trivial destructor}}136 137 constexpr UnionWithNonLiteralMemberExplicitDtor1() : x{} {}138 ~UnionWithNonLiteralMemberExplicitDtor1() = default; // expected-warning {{explicitly defaulted destructor is implicitly deleted}}139 // expected-note@-1 {{replace 'default' with 'delete'}}140};141#if __cplusplus >= 202002L142static_assert(__is_literal(UnionWithNonLiteralMemberExplicitDtor1), "fail");143#else144static_assert(!__is_literal(UnionWithNonLiteralMemberExplicitDtor1), "fail");145#endif146 147union UnionWithNonLiteralMemberExplicitDtor2 {148 HasDefaultCtorAndNonConstexprDtor x;149 int y;150 151 constexpr UnionWithNonLiteralMemberExplicitDtor2() : x{} {}152 ~UnionWithNonLiteralMemberExplicitDtor2() = delete;153};154static_assert(!__is_literal(UnionWithNonLiteralMemberExplicitDtor2), "fail");155 156#if __cplusplus >= 202002L157union UnionWithNonLiteralMemberConstexprDtor1 {158 HasDefaultCtorAndNonConstexprDtor x;159 int y;160 // expected-note@-2 {{destructor of 'UnionWithNonLiteralMemberConstexprDtor1' is implicitly deleted because variant field 'x' has a non-trivial destructor}}161 162 constexpr UnionWithNonLiteralMemberConstexprDtor1() : x{} {}163 constexpr ~UnionWithNonLiteralMemberConstexprDtor1() = default; // expected-warning {{explicitly defaulted destructor is implicitly deleted}}164 // expected-note@-1 {{replace 'default' with 'delete'}}165};166static_assert(__is_literal(UnionWithNonLiteralMemberConstexprDtor1), "fail");167 168union UnionWithNonLiteralMemberConstexprDtor2 {169 HasDefaultCtorAndNonConstexprDtor x;170 int y;171 172 constexpr UnionWithNonLiteralMemberConstexprDtor2() : x{} {}173 constexpr ~UnionWithNonLiteralMemberConstexprDtor2() = delete;174};175static_assert(__is_literal(UnionWithNonLiteralMemberConstexprDtor2), "fail");176#endif177}178#endif179