Templates in FPL?

[Fergus Henderson]

On 23-May-2001, D. Tweed <tweed@cs.bris.ac.uk> wrote:
> On 22 May 2001, Carl R. Witty wrote:
> 
> > "D. Tweed" <tweed@cs.bris.ac.uk> writes:
> > 
> > > In my experience the C++ idiom `you only pay for what you use' (==>
> > > templates are essentially type-checked macros) and the fact most compilers
> > > are evolved from C compilers makes working with templates a real pain in
> > > practice.
> > 
> > I'm not sure what you mean by type-checked here.  Templates are not
> > type-checked at definition time, but are type-checked when they are
> > used; the same is true of ordinary macros.
> 
> I was thinking in terms of (to take a really simple example)
> 
> template<class T>
> void
> initialiseArray(T** arr,const T& elt,int bnd)
...
> If I try and use intialiseArray(<obj of type foo>,<obj of type bar>), with
> the template function I get the error when passing in the parameters;

In other words, *calls to* template functions are type-checked at compile time.
However, *definitions of* template functions are only type-checked when they
are instantiated.

-- 
Fergus Henderson <fjh@cs.mu.oz.au>  |  "I have always known that the pursuit
                                    |  of excellence is a lethal habit"
WWW: <http://www.cs.mu.oz.au/~fjh>  |     -- the last words of T. S. Garp.