template4.c

this is a gcc file, you can download it and learn its usetility, for further detail please look at t

// Build don't link:

// Copyright (C) 1999 Free Software Foundation

// by Alexandre Oliva <[e-mail]>
// based on bug report by Andrey Slepuhin <[e-mail]>

template <const int&> struct X {};

int a = 1;
X<a> x; // ok, a has external linkage

const int b = 2;
X<b> y; // ERROR - const b has internal linkage

extern const int c;
X<c> z; // ok, c has external linkage

extern const int c = 3;
X<c> z_; // gets bogus error - using c as constant