implicit-member-functions.cpp
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// RUN: %clang_cc1 -fsyntax-only -verify -std=c++11 %s
struct A { };
A::A() { } // expected-error {{definition of implicitly declared default constructor}}
struct B { };
B::B(const B&) { } // expected-error {{definition of implicitly declared copy constructor}}
struct C { };
C& C::operator=(const C&) { return *this; } // expected-error {{definition of implicitly declared copy assignment operator}}
struct D { };
D::~D() { } // expected-error {{definition of implicitly declared destructor}}
// Make sure that the special member functions are introduced for
// name-lookup purposes and overload with user-declared
// constructors and assignment operators.
namespace PR6570 {
class A { };
class B {
public:
B() {}
B(const A& a) {
operator = (CONST);
operator = (a);
}
B& operator = (const A& a) {
return *this;
}
void f(const A &a) {
B b(a);
};
static const B CONST;
};
}
namespace PR7594 {
// If the lazy declaration of special member functions is triggered
// in an out-of-line initializer, make sure the functions aren't in
// the initializer scope. This used to crash Clang:
struct C {
C();
static C *c;
};
C *C::c = new C();
}
namespace Recursion {
template<typename T> struct InvokeCopyConstructor {
static const T &get();
typedef decltype(T(get())) type; // expected-error {{no matching conver}}
};
struct B;
struct A {
// expected-note@-1 {{while substituting deduced template arguments}}
typedef B type;
template<typename T,
typename = typename InvokeCopyConstructor<typename T::type>::type>
// expected-note@-1 {{in instantiation of template class}}
A(const T &);
// expected-note@-1 {{in instantiation of default argument}}
};
struct B { // expected-note {{while declaring the implicit copy constructor for 'B'}}
// expected-note@-1 {{candidate constructor (the implicit move }}
B(); // expected-note {{candidate constructor not viable}}
A a;
};
// Triggering the declaration of B's copy constructor causes overload
// resolution to occur for A's copying constructor, which instantiates
// InvokeCopyConstructor<B>, which triggers the declaration of B's copy
// constructor. Notionally, this happens when we get to the end of the
// definition of 'struct B', so there is no declared copy constructor yet.
//
// This behavior is g++-compatible, but isn't exactly right; the class is
// supposed to be incomplete when we implicitly declare its special members.
B b = B();
// Another case, which isn't ill-formed under our rules. This is inspired by
// a problem which occurs when combining CGAL with libstdc++-4.7.
template<typename T> T &&declval();
template<typename T, typename U> struct pair {
pair();
template<typename V, typename W,
typename = decltype(T(declval<const V&>())),
typename = decltype(U(declval<const W&>()))>
pair(const pair<V,W> &);
};
template<typename K> struct Line;
template<typename K> struct Vector {
Vector(const Line<K> &l);
};
template<typename K> struct Point {
Vector<K> v;
};
template<typename K> struct Line {
pair<Point<K>, Vector<K>> x;
};
// Trigger declaration of Line copy ctor, which causes substitution into
// pair's templated constructor, which triggers instantiation of the
// definition of Point's copy constructor, which performs overload resolution
// on Vector's constructors, which requires declaring all of Line's
// constructors. That should not find a copy constructor (because we've not
// declared it yet), but by the time we get all the way back here, we should
// find the copy constructor.
Line<void> L1;
Line<void> L2(L1);
}