llvm-project/clang/test/CXX/drs/dr16xx.cpp

// RUN: %clang_cc1 -std=c++98 -triple x86_64-unknown-unknown %s -verify -fexceptions -fcxx-exceptions -pedantic-errors
// RUN: %clang_cc1 -std=c++11 -triple x86_64-unknown-unknown %s -verify -fexceptions -fcxx-exceptions -pedantic-errors
// RUN: %clang_cc1 -std=c++14 -triple x86_64-unknown-unknown %s -verify -fexceptions -fcxx-exceptions -pedantic-errors
// RUN: %clang_cc1 -std=c++1z -triple x86_64-unknown-unknown %s -verify -fexceptions -fcxx-exceptions -pedantic-errors

#if __cplusplus < 201103L
// expected-error@+1 {{variadic macro}}
#define static_assert(...) __extension__ _Static_assert(__VA_ARGS__)
#endif

namespace dr1611 { // dr1611: dup 1658
  struct A { A(int); };
  struct B : virtual A { virtual void f() = 0; };
  struct C : B { C() : A(0) {} void f(); };
  C c;
}

namespace dr1684 { // dr1684: 3.6
#if __cplusplus >= 201103L
  struct NonLiteral { // expected-note {{because}}
    NonLiteral();
    constexpr int f() { return 0; } // expected-warning 0-1{{will not be implicitly 'const'}}
  };
  constexpr int f(NonLiteral &) { return 0; }
  constexpr int f(NonLiteral) { return 0; } // expected-error {{not a literal type}}
#endif
}

namespace dr1631 {  // dr1631: 3.7
#if __cplusplus >= 201103L
  // Incorrect overload resolution for single-element initializer-list

  struct A { int a[1]; };
  struct B { B(int); };
  void f(B, int);
  void f(B, int, int = 0);
  void f(int, A);

  void test() {
    f({0}, {{1}}); // expected-warning {{braces around scalar init}}
  }

  namespace with_error {
    void f(B, int);           // TODO: expected- note {{candidate function}}
    void f(int, A);           // expected-note {{candidate function}}
    void f(int, A, int = 0);  // expected-note {{candidate function}}
    
    void test() {
      f({0}, {{1}});        // expected-error{{call to 'f' is ambiguous}}
    }
  }
#endif
}

namespace dr1638 { // dr1638: yes
#if __cplusplus >= 201103L
  template<typename T> struct A {
    enum class E; // expected-note {{previous}}
    enum class F : T; // expected-note 2{{previous}}
  };

  template<> enum class A<int>::E;
  template<> enum class A<int>::E {};
  template<> enum class A<int>::F : int;
  template<> enum class A<int>::F : int {};

  template<> enum class A<short>::E : int;
  template<> enum class A<short>::E : int {};

  template<> enum class A<short>::F; // expected-error {{different underlying type}}
  template<> enum class A<char>::E : char; // expected-error {{different underlying type}}
  template<> enum class A<char>::F : int; // expected-error {{different underlying type}}

  enum class A<unsigned>::E; // expected-error {{template specialization requires 'template<>'}} expected-error {{nested name specifier}}
  template enum class A<unsigned>::E; // expected-error {{enumerations cannot be explicitly instantiated}}
  enum class A<unsigned>::E *e; // expected-error {{must use 'enum' not 'enum class'}}

  struct B {
    friend enum class A<unsigned>::E; // expected-error {{must use 'enum' not 'enum class'}}
  };
#endif
}

namespace dr1645 { // dr1645: 3.9
#if __cplusplus >= 201103L
  struct A {
    constexpr A(int, float = 0); // expected-note 2{{candidate}}
    explicit A(int, int = 0); // expected-note 2{{candidate}}
    A(int, int, int = 0) = delete; // expected-note {{candidate}}
  };

  struct B : A { // expected-note 2{{candidate}}
    using A::A; // expected-note 5{{inherited here}}
  };

  constexpr B a(0); // expected-error {{ambiguous}}
  constexpr B b(0, 0); // expected-error {{ambiguous}}
#endif
}

namespace dr1653 { // dr1653: 4 c++17
  void f(bool b) {
    ++b;
    b++;
#if __cplusplus <= 201402L
    // expected-warning@-3 {{deprecated}} expected-warning@-2 {{deprecated}}
#else
    // expected-error@-5 {{incrementing expression of type bool}} expected-error@-4 {{incrementing expression of type bool}}
#endif
    --b; // expected-error {{cannot decrement expression of type bool}}
    b--; // expected-error {{cannot decrement expression of type bool}}
    b += 1; // ok
    b -= 1; // ok
  }
}

namespace dr1658 { // dr1658: 5
  namespace DefCtor {
    class A { A(); }; // expected-note 0-2{{here}}
    class B { ~B(); }; // expected-note 0-2{{here}}

    // The stars align! An abstract class does not construct its virtual bases.
    struct C : virtual A { C(); virtual void foo() = 0; };
    C::C() = default; // ok, not deleted, expected-error 0-1{{extension}}
    struct D : virtual B { D(); virtual void foo() = 0; };
    D::D() = default; // ok, not deleted, expected-error 0-1{{extension}}

    // In all other cases, we are not so lucky.
    struct E : A { E(); virtual void foo() = 0; };
#if __cplusplus < 201103L
    E::E() = default; // expected-error {{private default constructor}} expected-error {{extension}} expected-note {{here}}
#else
    E::E() = default; // expected-error {{would delete}} expected-note@-4{{inaccessible default constructor}}
#endif
    struct F : virtual A { F(); };
#if __cplusplus < 201103L
    F::F() = default; // expected-error {{private default constructor}} expected-error {{extension}} expected-note {{here}}
#else
    F::F() = default; // expected-error {{would delete}} expected-note@-4{{inaccessible default constructor}}
#endif

    struct G : B { G(); virtual void foo() = 0; };
#if __cplusplus < 201103L
    G::G() = default; // expected-error@-2 {{private destructor}} expected-error {{extension}} expected-note {{here}}
#else
    G::G() = default; // expected-error {{would delete}} expected-note@-4{{inaccessible destructor}}
#endif
    struct H : virtual B { H(); };
#if __cplusplus < 201103L
    H::H() = default; // expected-error@-2 {{private destructor}} expected-error {{extension}} expected-note {{here}}
#else
    H::H() = default; // expected-error {{would delete}} expected-note@-4{{inaccessible destructor}}
#endif
  }

  namespace Dtor {
    class B { ~B(); }; // expected-note 0-2{{here}}

    struct D : virtual B { ~D(); virtual void foo() = 0; };
    D::~D() = default; // ok, not deleted, expected-error 0-1{{extension}}

    struct G : B { ~G(); virtual void foo() = 0; };
#if __cplusplus < 201103L
    G::~G() = default; // expected-error@-2 {{private destructor}} expected-error {{extension}} expected-note {{here}}
#else
    G::~G() = default; // expected-error {{would delete}} expected-note@-4{{inaccessible destructor}}
#endif
    struct H : virtual B { ~H(); };
#if __cplusplus < 201103L
    H::~H() = default; // expected-error@-2 {{private destructor}} expected-error {{extension}} expected-note {{here}}
#else
    H::~H() = default; // expected-error {{would delete}} expected-note@-4{{inaccessible destructor}}
#endif
  }

  namespace MemInit {
    struct A { A(int); }; // expected-note {{here}}
    struct B : virtual A {
      B() {}
      virtual void f() = 0;
    };
    struct C : virtual A {
      C() {} // expected-error {{must explicitly initialize}}
    };
  }

  namespace CopyCtorParamType {
    struct A { A(A&); };
    struct B : virtual A { virtual void f() = 0; };
    struct C : virtual A { virtual void f(); };
    struct D : A { virtual void f() = 0; };

    struct X {
      friend B::B(const B&) throw();
      friend C::C(C&);
      friend D::D(D&);
    };
  }

  namespace CopyCtor {
    class A { A(const A&); A(A&&); }; // expected-note 0-4{{here}} expected-error 0-1{{extension}}

    struct C : virtual A { C(const C&); C(C&&); virtual void foo() = 0; }; // expected-error 0-1{{extension}}
    C::C(const C&) = default; // expected-error 0-1{{extension}}
    C::C(C&&) = default; // expected-error 0-2{{extension}}

    struct E : A { E(const E&); E(E&&); virtual void foo() = 0; }; // expected-error 0-1{{extension}}
#if __cplusplus < 201103L
    E::E(const E&) = default; // expected-error {{private copy constructor}} expected-error {{extension}} expected-note {{here}}
    E::E(E&&) = default; // expected-error {{private move constructor}} expected-error 2{{extension}} expected-note {{here}}
#else
    E::E(const E&) = default; // expected-error {{would delete}} expected-note@-5{{inaccessible copy constructor}}
    E::E(E&&) = default; // expected-error {{would delete}} expected-note@-6{{inaccessible move constructor}}
#endif
    struct F : virtual A { F(const F&); F(F&&); }; // expected-error 0-1{{extension}}
#if __cplusplus < 201103L
    F::F(const F&) = default; // expected-error {{private copy constructor}} expected-error {{extension}} expected-note {{here}}
    F::F(F&&) = default; // expected-error {{private move constructor}} expected-error 2{{extension}} expected-note {{here}}
#else
    F::F(const F&) = default; // expected-error {{would delete}} expected-note@-5{{inaccessible copy constructor}}
    F::F(F&&) = default; // expected-error {{would delete}} expected-note@-6{{inaccessible move constructor}}
#endif
  }

  // assignment case is superseded by dr2180
}

namespace dr1672 { // dr1672: 7
  struct Empty {};
  struct A : Empty {};
  struct B { Empty e; };
  struct C : A { B b; int n; };
  struct D : A { int n; B b; };

  static_assert(!__is_standard_layout(C), "");
  static_assert(__is_standard_layout(D), "");

  struct E { B b; int n; };
  struct F { int n; B b; };
  union G { B b; int n; };
  union H { int n; B b; };

  struct X {};
  template<typename T> struct Y : X, A { T t; };

  static_assert(!__is_standard_layout(Y<E>), "");
  static_assert(__is_standard_layout(Y<F>), "");
  static_assert(!__is_standard_layout(Y<G>), "");
  static_assert(!__is_standard_layout(Y<H>), "");
  static_assert(!__is_standard_layout(Y<X>), "");
}