[basic.def] (original) (raw)

:

All but one of the following are definitions:

int a; // defines a extern const int c = 1; // defines c int f(int x) { return x+a; } // defines f and defines x struct S { int a; int b; }; // defines S, S​::​a, and S​::​b struct X { // defines X int x; // defines non-static data member x static int y; // declares static data member y X(): x(0) { } // defines a constructor of X }; int X::y = 1; // defines X​::​y enum { up, down }; // defines up and down namespace N { int d; } // defines N and N​::​d namespace N1 = N; // defines N1 X anX; // defines anX

whereas these are just declarations:

extern int a; // declares a extern const int c; // declares c int f(int); // declares f struct S; // declares S typedef int Int; // declares Int extern X anotherX; // declares anotherX using N::d; // declares d

— end example