Viewing file:  linkage2.C (1.09 KB) -rw-r--r--
Select action/file-type:
 (+) |  (+) |  (+) | Code (+) | Session (+) |  (+) | SDB (+) |  (+) |  (+) |  (+) |  (+) |  (+) |
// DR 743: A type without linkage shall not be used as the type of a
// variable or function with linkage, unless
// o the variable or function has extern "C" linkage (7.5 [dcl.link]), or
// o the variable or function is not used (3.2 [basic.def.odr]) or is
// defined in the same translation unit.
// { dg-do compile { target c++11 } }
template <typename T> struct B {
void g(T){}
void h(T); // { dg-error "never defined" }
friend void i(B, T){}
static T t1; // { dg-error "never defined" }
static T t2;
};
template <typename T> T B<T>::t2 = { };
enum { E1 } e1; // OK, defined
extern enum { E2 } e2; // { dg-error "never defined" }
extern "C" enum { E3 } e3; // OK, extern "C"
void f() {
struct A { int x; }; // no linkage
A a = {1};
B<A> ba; // declares B<A>::g(A) and B<A>::h(A)
ba.t1 = a; // error, B<T>::t never defined
ba.t2 = a; // OK
ba.g(a); // OK
ba.h(a); // error, B<T>::h never defined
i(ba, a); // OK
e1+e2+e3; // { dg-warning "arithmetic between different enumeration types" "" { target c++20 } }
}
|
