llvm-for-llvmta/tools/clang/test/CXX/dcl.decl/dcl.decomp/p4.cpp

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2022-04-25 13:02:35 +02:00
// RUN: %clang_cc1 -std=c++1z -verify -triple i686-linux-gnu %s
template<typename T, typename U> struct same;
template<typename T> struct same<T, T> { ~same(); };
struct Empty {};
struct A {
int a;
};
namespace NonPublicMembers {
struct NonPublic1 {
protected:
int a; // expected-note {{declared protected here}}
};
struct NonPublic2 {
private:
int a; // expected-note 2{{declared private here}}
};
struct NonPublic3 : private A {}; // expected-note {{declared private here}}
struct NonPublic4 : NonPublic2 {};
void test() {
auto [a1] = NonPublic1(); // expected-error {{cannot decompose protected member 'a' of 'NonPublicMembers::NonPublic1'}}
auto [a2] = NonPublic2(); // expected-error {{cannot decompose private member 'a' of 'NonPublicMembers::NonPublic2'}}
auto [a3] = NonPublic3(); // expected-error {{cannot decompose members of inaccessible base class 'A' of 'NonPublicMembers::NonPublic3'}}
auto [a4] = NonPublic4(); // expected-error {{cannot decompose private member 'a' of 'NonPublicMembers::NonPublic2'}}
}
}
namespace AnonymousMember {
struct Struct {
struct { // expected-note {{declared here}}
int i;
};
};
struct Union {
union { // expected-note {{declared here}}
int i;
};
};
void test() {
auto [a1] = Struct(); // expected-error {{cannot decompose class type 'AnonymousMember::Struct' because it has an anonymous struct member}}
auto [a2] = Union(); // expected-error {{cannot decompose class type 'AnonymousMember::Union' because it has an anonymous union member}}
}
}
namespace MultipleClasses {
struct B : A {
int a;
};
struct C { int a; };
struct D : A, C {};
struct E : virtual A {};
struct F : A, E {}; // expected-warning {{direct base 'A' is inaccessible due to ambiguity}}
struct G : virtual A {};
struct H : E, G {};
struct I { int i; };
struct J : I {};
struct K : I, virtual J {}; // expected-warning {{direct base 'MultipleClasses::I' is inaccessible due to ambiguity}}
struct L : virtual J {};
struct M : virtual J, L {};
void test() {
auto [b] = B(); // expected-error {{cannot decompose class type 'B': both it and its base class 'A' have non-static data members}}
auto [d] = D(); // expected-error {{cannot decompose class type 'D': its base classes 'A' and 'MultipleClasses::C' have non-static data members}}
auto [e] = E();
auto [f] = F(); // expected-error-re {{cannot decompose members of ambiguous base class 'A' of 'F':{{.*}}struct MultipleClasses::F -> struct A{{.*}}struct MultipleClasses::F -> struct MultipleClasses::E -> struct A}}
auto [h] = H(); // ok, only one (virtual) base subobject even though there are two paths to it
auto [k] = K(); // expected-error {{cannot decompose members of ambiguous base class 'MultipleClasses::I'}}
auto [m] = M(); // ok, all paths to I are through the same virtual base subobject J
same<decltype(m), int>();
}
}
namespace BindingTypes {
struct A {
int i = 0;
int &r = i;
const float f = i;
mutable volatile int mvi;
};
void e() {
auto [i,r,f,mvi] = A();
same<decltype(i), int>();
same<decltype(r), int&>();
same<decltype(f), const float>();
same<decltype(mvi), volatile int>();
same<decltype((i)), int&>();
same<decltype((r)), int&>();
same<decltype((f)), const float&>();
same<decltype((mvi)), volatile int&>();
}
void f() {
auto &&[i,r,f,mvi] = A();
same<decltype(i), int>();
same<decltype(r), int&>();
same<decltype(f), const float>();
same<decltype(mvi), volatile int>();
same<decltype((i)), int&>();
same<decltype((r)), int&>();
same<decltype((f)), const float&>();
same<decltype((mvi)), volatile int&>();
}
void g() {
const auto [i,r,f,mvi] = A();
same<decltype(i), const int>();
same<decltype(r), int&>();
same<decltype(f), const float>();
same<decltype(mvi), volatile int>(); // not 'const volatile int', per expected resolution of DRxxx
same<decltype((i)), const int&>();
same<decltype((r)), int&>();
same<decltype((f)), const float&>();
same<decltype((mvi)), volatile int&>(); // not 'const volatile int&', per expected resolution of DRxxx
}
void h() {
typedef const A CA;
auto &[i,r,f,mvi] = CA(); // type of var is 'const A &'
same<decltype(i), const int>(); // not 'int', per expected resolution of DRxxx
same<decltype(r), int&>();
same<decltype(f), const float>();
same<decltype(mvi), volatile int>(); // not 'const volatile int', per expected resolution of DRxxx
same<decltype((i)), const int&>(); // not 'int&', per expected resolution of DRxxx
same<decltype((r)), int&>();
same<decltype((f)), const float&>();
same<decltype((mvi)), volatile int&>(); // not 'const volatile int&', per expected resolution of DRxxx
}
struct B {
mutable int i;
};
void mut() {
auto [i] = B();
const auto [ci] = B();
volatile auto [vi] = B();
same<decltype(i), int>();
same<decltype(ci), int>();
same<decltype(vi), volatile int>();
}
}
namespace Bitfield {
struct S { unsigned long long x : 4, y : 32; int z; }; // expected-note 2{{here}}
int f(S s) {
auto [a, b, c] = s;
unsigned long long &ra = a; // expected-error {{bit-field 'x'}}
unsigned long long &rb = b; // expected-error {{bit-field 'y'}}
int &rc = c;
// the type of the binding is the type of the field
same<decltype(a), unsigned long long>();
same<decltype(b), unsigned long long>();
// the type of the expression is an lvalue of the field type
// (even though a reference can't bind to the field)
same<decltype((a)), unsigned long long&>();
same<decltype((b)), unsigned long long&>();
// the expression promotes to a type large enough to hold the result
same<decltype(+a), int>();
same<decltype(+b), unsigned int>();
return rc;
}
}
namespace Constexpr {
struct Q { int a, b; constexpr Q() : a(1), b(2) {} };
constexpr Q q;
auto &[qa, qb] = q;
static_assert(&qa == &q.a && &qb == &q.b);
static_assert(qa == 1 && qb == 2);
}
namespace std_example {
struct S { int x1 : 2; volatile double y1; };
S f();
const auto [x, y] = f();
same<decltype((x)), const int&> same1;
same<decltype((y)), const volatile double&> same2;
}
namespace p0969r0 {
struct A {
int x;
int y;
};
struct B : private A { // expected-note {{declared private here}}
void test_member() {
auto &[x, y] = *this;
}
friend void test_friend(B);
};
void test_friend(B b) {
auto &[x, y] = b;
}
void test_external(B b) {
auto &[x, y] = b; // expected-error {{cannot decompose members of inaccessible base class 'p0969r0::A' of 'p0969r0::B'}}
}
struct C {
int x;
protected:
int y; // expected-note {{declared protected here}} expected-note {{can only access this member on an object of type 'p0969r0::D'}}
void test_member() {
auto &[x, y] = *this;
}
friend void test_friend(struct D);
};
struct D : C {
static void test_member(D d, C c) {
auto &[x1, y1] = d;
auto &[x2, y2] = c; // expected-error {{cannot decompose protected member 'y' of 'p0969r0::C'}}
}
};
void test_friend(D d) {
auto &[x, y] = d;
}
void test_external(D d) {
auto &[x, y] = d; // expected-error {{cannot decompose protected member 'y' of 'p0969r0::C'}}
}
}