how to forward declare and then define a template function?

[ausairman]

Hello,
I'm trying to forward-declare a template function outside of main() like this:

template <class typ> void memshift(typ arr [], int src, int dest, typ & cont);

I don't get any compile errors so hopefully that means it's right (??). But then how do I define the function inside main()? Like this?

template <class typ> void memshift(typ arr [], int src, int dest, typ & cont) {
    //function here
}

When I do that I get the following error: error: expected primary-expression before "template"

What have I missed/done wrong?

[zb0S216C]

ausairman wrote:

I don't get any compile errors so hopefully that means it's right

If the compiler doesn't complain, it doesn't always mean there's nothing wrong.

ausairman wrote:

But then how do I define the function inside main()?

You can't define a function within another function. You need to either define the function body at the point of declaration, or define the body after main( ).

_Wazzak

[ausairman]

So how would I create this function:

void myfun(int input) {
  return input * SOMESTAT;
}

where SOMESTAT is a variable defined by another function?

[zb0S216C]

ausairman wrote:

So how would I create this function:

void myfun(int input) {
  return input * SOMESTAT;
}

It's right in front of you; you've just written it. Unless you meant something else?

ausairman wrote:

where SOMESTAT is a variable defined by another function?

A variable defined within a function goes out of scope when the function returns.

_Wazzak

[kev82]

So how would I create this function:

void myfun(int input) {
  return input * SOMESTAT;
}

where SOMESTAT is a variable defined by another function?

If somestat is an integer known at compile time, then can do with a template, but this does not seem particularly sensible. The alternative would be

int myfun_general(int input, int somestat)
  return input*somestat;
}

boost::bind(myfun_general, _1, valueForSomestat)

The bind returns a functor, that takes one argument, and when called, calls myfun_general(arg, valueForSomestat)