Re: Ada generics

["Hyman Rosen" <hyman.rosen@gmail.com>]

Dmitry A. Kazakov wrote:
> When you compare values of potentially different objects instead, then
> the semantics of the comparison is not necessarily identity. In fact, it is
> outside the language.

I think the issue here is not unlike that faced by programming
languages when dealing with Unicode in identifiers. (I took a quick
glance through AI-285.) There are potentially several ways that a
character can be written in the source text, and the compilers must
decide what it is that is written, and which forms must be considered
identical and which distinct. There is certainly no problem in defining
by fiat the semantics for doing template floating-point arithmetic, but
the committee didn't think it was worth the effort. It's the sort of
thing that Ada goes through with its universal floats, but at least
there the application is of wider use.

> I don't see what systems programming has to do with templates.

C++ was written as an enhancement for people already using C. It gave
those people a great deal of extra expressive power, but they would not
have given up what they already had.