Since the function doesn't depend on the template parameter, the compiler can condense all instantiations into a single function.
I don't know why you get 1 for the address.
I experimented with my real code, and concluded that what @Mark said above is very important here :
Since the function doesn't depend on the template parameter, the compiler can condense all instantiations into a single function.
I also came to a conclusion that if the function-body depends on T*, not on T, it still produces the same function for different type arguments in my real code (not on ideone, though). However, if it depends on T, then it produces different functions, because sizeof(T) differs (fortunately for me) for different type arguments.
So I added a dummy automatic variable of type T in the function template, so that the function could depend on the size of T so as to force it to produce different functions.