p13-0x.cpp
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// RUN: %clang_cc1 -std=c++11 -fsyntax-only -verify %s
// If the implicitly-defined constructor would satisfy the requirements of a
// constexpr constructor, the implicitly-defined constructor is constexpr.
struct Constexpr1 {
constexpr Constexpr1() : n(0) {}
int n;
};
constexpr Constexpr1 c1a = Constexpr1(Constexpr1()); // ok
constexpr Constexpr1 c1b = Constexpr1(Constexpr1(c1a)); // ok
struct Constexpr2 {
Constexpr1 ce1;
constexpr Constexpr2() = default;
constexpr Constexpr2(const Constexpr2 &o) : ce1(o.ce1) {}
// no move constructor
};
constexpr Constexpr2 c2a = Constexpr2(Constexpr2()); // ok
constexpr Constexpr2 c2b = Constexpr2(Constexpr2(c2a)); // ok
struct Constexpr3 {
Constexpr2 ce2;
// all special constructors are constexpr, move ctor calls ce2's copy ctor
};
constexpr Constexpr3 c3a = Constexpr3(Constexpr3()); // ok
constexpr Constexpr3 c3b = Constexpr3(Constexpr3(c3a)); // ok
struct NonConstexprCopy {
constexpr NonConstexprCopy() = default;
NonConstexprCopy(const NonConstexprCopy &);
constexpr NonConstexprCopy(NonConstexprCopy &&) = default;
int n = 42;
};
NonConstexprCopy::NonConstexprCopy(const NonConstexprCopy &) = default; // expected-note {{here}}
constexpr NonConstexprCopy ncc1 = NonConstexprCopy(NonConstexprCopy()); // ok
constexpr NonConstexprCopy ncc2 = ncc1; // expected-error {{constant expression}} expected-note {{non-constexpr constructor}}
struct NonConstexprDefault {
NonConstexprDefault() = default;
constexpr NonConstexprDefault(int n) : n(n) {}
int n;
};
struct Constexpr4 {
NonConstexprDefault ncd;
};
constexpr NonConstexprDefault ncd = NonConstexprDefault(NonConstexprDefault(1));
constexpr Constexpr4 c4a = { ncd };
constexpr Constexpr4 c4b = Constexpr4(c4a);
constexpr Constexpr4 c4c = Constexpr4(static_cast<Constexpr4&&>(const_cast<Constexpr4&>(c4b)));
struct Constexpr5Base {};
struct Constexpr5 : Constexpr5Base { constexpr Constexpr5() {} };
constexpr Constexpr5 ce5move = Constexpr5();
constexpr Constexpr5 ce5copy = ce5move;
// An explicitly-defaulted constructor doesn't become constexpr until the end of
// its class. Make sure we note that the class has a constexpr constructor when
// that happens.
namespace PR13052 {
template<typename T> struct S {
S() = default; // expected-note 2{{here}}
S(S&&) = default;
S(const S&) = default;
T t;
};
struct U {
U() = default;
U(U&&) = default;
U(const U&) = default;
};
struct V {
V(); // expected-note {{here}}
V(V&&) = default;
V(const V&) = default;
};
struct W {
W(); // expected-note {{here}}
};
static_assert(__is_literal_type(U), "");
static_assert(!__is_literal_type(V), "");
static_assert(!__is_literal_type(W), "");
static_assert(__is_literal_type(S<U>), "");
static_assert(!__is_literal_type(S<V>), "");
static_assert(!__is_literal_type(S<W>), "");
struct X {
friend constexpr U::U() noexcept;
friend constexpr U::U(U&&) noexcept;
friend constexpr U::U(const U&) noexcept;
friend constexpr V::V(); // expected-error {{follows non-constexpr declaration}}
friend constexpr V::V(V&&) noexcept;
friend constexpr V::V(const V&) noexcept;
friend constexpr W::W(); // expected-error {{follows non-constexpr declaration}}
friend constexpr W::W(W&&) noexcept;
friend constexpr W::W(const W&) noexcept;
friend constexpr S<U>::S() noexcept;
friend constexpr S<U>::S(S<U>&&) noexcept;
friend constexpr S<U>::S(const S<U>&) noexcept;
friend constexpr S<V>::S(); // expected-error {{follows non-constexpr declaration}}
friend constexpr S<V>::S(S<V>&&) noexcept;
friend constexpr S<V>::S(const S<V>&) noexcept;
friend constexpr S<W>::S(); // expected-error {{follows non-constexpr declaration}}
friend constexpr S<W>::S(S<W>&&) noexcept;
friend constexpr S<W>::S(const S<W>&) noexcept;
};
}
namespace Mutable {
struct A {
constexpr A(A &);
A(const A &);
};
struct B {
constexpr B(const B &) = default; // ok
mutable A a;
};
struct C {
constexpr C(const C &) = default; // expected-error {{not constexpr}}
A a;
};
}