With normal functions, the declaration and definition are often separated across multiple files like so:

// Foo.h

namespace Foo
{
    void Bar();
}

.

// Foo.cpp

#include "Foo.h"

void Foo::Bar()
{
    cout << "Inside function." << endl;
}

It is my understanding that this cannot be done with templates. The declaration and definition must not be separate because the appropriate form of the template is created "on-demand" when needed.

So, how and where are templates typically defined in a multiple-file project like this? My intuition is that it would be in Foo.cpp because that's where the "meat" of functions normally is, but on the other hand it's the header file that's going to be included.