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// RUN: %clang_cc1 -std=c++1z -verify %s
// Test that we cope with failure to expand a pack.
template<typename ...T> struct Unexpanded : T... {
using T::f; // expected-error {{unexpanded}}
using typename T::type; // expected-error {{unexpanded}}
template<typename ...U> void g(U ...u) { f(u...); } // expected-error {{undeclared identifier 'f'}}
void h() {
Unexpanded<type...> *p; // expected-error {{undeclared identifier 'type'}}
}
};
void test_Unexpanded() {
struct A { void f(); }; // expected-note {{must qualify}}
struct B { void f(int); }; // expected-note {{must qualify}}
Unexpanded<A, B>().g(0); // expected-note {{instantiation of}}
}
// Test using non-type members from pack of base classes.
template<typename ...T> struct A : T... { // expected-note 2{{candidate}}
using T::T ...; // expected-note 2{{inherited here}}
using T::operator() ...;
using T::operator T* ...;
using T::h ...;
void f(int n) { h(n); } // expected-error {{ambiguous}}
void f(int n, int m) { h(n, m); } // expected-error {{member using declaration 'h' instantiates to an empty pack}}
void g(int n) { (*this)(n); } // expected-error {{ambiguous}}
void g(int n, int m) { (*this)(n, m); } // expected-error {{does not provide a call operator}}
};
namespace test_A {
struct X {
X();
X(int); // expected-note {{candidate}}
void operator()(int); // expected-note 2{{candidate}}
operator X *();
void h(int); // expected-note {{candidate}}
};
struct Y {
Y();
Y(int, int);
void operator()(int, int);
operator Y *();
void h(int, int); // expected-note {{not viable}}
};
struct Z {
Z();
Z(int); // expected-note {{candidate}}
void operator()(int); // expected-note 2{{candidate}}
operator Z *();
void h(int); // expected-note {{candidate}}
};
void f() {
A<> a;
a.f(0, 0); // expected-note {{instantiation of}}
a.g(0, 0); // expected-note {{instantiation of}}
A<X, Y> axy(0);
A<X, Y>(0, 0);
axy.f(0);
axy.f(0, 0);
axy.g(0);
axy.g(0, 0);
axy(0);
axy(0, 0);
A<X, Y, Z>(0); // expected-error {{ambiguous}}
A<X, Y, Z> axyz(0, 0);
axyz.f(0); // expected-note {{instantiation of}}
axyz.f(0, 0);
axyz.g(0); // expected-note {{instantiation of}}
axyz.g(0, 0);
axyz(0); // expected-error {{ambiguous}}
axyz(0, 0);
X *x;
x = a; // expected-error {{incompatible}}
x = axy;
x = axyz;
x = a.operator X*(); // expected-error {{no member}}
x = axy.operator X*();
x = axyz.operator X*();
Z *z;
z = axyz;
z = axyz.operator Z*();
}
}
// Test using pack of non-type members from single base class.
template<typename X, typename Y, typename ...T> struct B : X, Y {
using X::operator T* ...;
};
namespace test_B {
struct X { operator int*(); operator float*(); operator char*(); }; // expected-note {{candidate}}
struct Y { operator int*(); operator float*(); operator char*(); }; // expected-note {{candidate}}
B<X, Y, int, float> bif;
int *pi = bif;
float *pf = bif;
char *pc = bif; // expected-error {{ambiguous}}
}
// Test using type member from pack of base classes.
template<typename ...T> struct C : T... {
using typename T::type ...; // expected-error {{target of using declaration conflicts}}
void f() { type value; } // expected-error {{member using declaration 'type' instantiates to an empty pack}}
};
namespace test_C {
struct X { typedef int type; };
struct Y { typedef int type; }; // expected-note {{conflicting}}
struct Z { typedef float type; }; // expected-note {{target}}
void f() {
C<> c;
c.f(); // expected-note {{instantiation of}}
C<X, Y> cxy;
cxy.f();
C<X, Y, Z> cxyz; // expected-note {{instantiation of}}
cxyz.f();
}
}
// Test using pack of non-types at block scope.
template<typename ...T> int fn1() {
using T::e ...; // expected-error 2{{class member}} expected-note 2{{instead}}
// expected-error@-1 2{{produces multiple values}}
return e; // expected-error {{using declaration 'e' instantiates to an empty pack}}
}
namespace test_fn1 {
struct X { static int e; };
struct Y { typedef int e; };
inline namespace P { enum E { e }; }
inline namespace Q { enum F { e }; }
void f() {
fn1<>(); // expected-note {{instantiation of}}
fn1<X>(); // expected-note {{instantiation of}}
fn1<Y>(); // expected-note {{instantiation of}}
fn1<E>();
fn1<E, F>(); // expected-note {{instantiation of}}
fn1<E, X>(); // expected-note {{instantiation of}}
}
}
// Test using pack of types at block scope.
template<typename ...T> void fn2() {
// This cannot ever be valid: in order for T::type to be a type, T must be a
// class, and a class member cannot be named by a block-scope using declaration.
using typename T::type ...; // expected-error {{class member}}
type x; // expected-error {{unknown type name 'type'}}
}
// Test partial substitution into class-scope pack.
template<typename ...T> auto lambda1() {
return [](auto x) {
struct A : T::template X<decltype(x)>... { // expected-note 1+{{instantiation of}}
using T::template X<decltype(x)>::f ...;
using typename T::template X<decltype(x)>::type ...;
void g(int n) { f(n); } // expected-error {{empty pack}} expected-error {{expected 2, have 1}} expected-error {{ambiguous}}
void h() { type value; } // expected-error {{empty pack}}
};
return A();
};
}
namespace test_lambda1 {
struct A {
template<typename> struct X {
void f(int); // expected-note {{candidate}}
using type = int;
};
};
struct B {
template<typename> struct X {
void f(int, int); // expected-note {{declared here}} expected-note {{not viable}}
using type = int;
};
};
struct C {
template<typename> struct X {
void f(int); // expected-note {{candidate}}
void f(int, int); // expected-note {{not viable}}
using type = int;
};
};
void f() {
lambda1<>() // expected-note 2{{instantiation of}}
(0)
// FIXME: This is poor error recovery
.g(0); // expected-error {{no member named 'g'}}
lambda1<A>()
(0)
.g(0);
lambda1<B>()
(0) // expected-note {{instantiation of}}
.g(0);
lambda1<A, B, C>()
(0) // expected-note {{instantiation of}}
.g(0);
}
}
namespace p0195r2_example {
template<typename ...Ts>
struct Overloader : Ts... {
using Ts::operator() ...;
};
template<typename ...Ts>
constexpr auto make_overloader(Ts &&...ts) {
return Overloader<Ts...>{static_cast<Ts&&>(ts)...};
}
void test() {
auto o = make_overloader(
[&](int &r) -> int & { return r; }, // expected-note {{candidate function}}
[&](float &r) -> float & { return r; } // expected-note {{candidate function}}
);
int a; float f; double d;
int &ra = o(a);
float &rf = o(f);
double &rd = o(d); // expected-error {{no matching function}}
}
}
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