is it possible to size a pointer's target?

[Erik]

Tom St Denis skrev:
> The only way a function can know the length of an array pointed to by a
> pointer is by the caller passing that information to the function.
>
> Probably the best way if you want to clear up the clutter is to use a
> struct which has both a pointer and length (maybe stored as an int).
>   
Length as an int?!? Sounds weird. What are negative values supposed to
mean? It has to be an unsigned type, maybe size_t.