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From: Hyman Rosen <hyrosen@mail.com>
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Subject: Re: why learn C?
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Date: Thu, 12 Apr 2007 15:28:58 GMT
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adaworks@sbcglobal.net wrote:
> This tends to increase, not decrease, the dependability since each
 > instantiation is checked at compile-time.

Every C++ template instantiation is done, and therefore checked,
at compile-time. It's Ada that has run-time instantiation (with
compile-time checking).

>>           Time end = integrate_until(f1 * phase_shift(f2,start) / f3 + f4, q);
>>           even though f1, f2, f3, and f4 were possibly of different types.
> In fact, your acknowledgement of the "different types" is quite telling.

Telling of what? Automatic instantiation lets generic functions come
into being as programs use them.

> Further, the ad hoc pointer is potentially problematic.

What pointer? I see no pointer in this code.

> A similar construct in Ada, using an access to a function, requires the
 > function to be type conformant and parameter conformant prior to being
 > incorporated into the construct.

The C++ code has no pointers at all. The automatic instantiation done by
the C++ template mechanism is similar in its goals to Ada's operator
overloading. A universe of candidate functions is searched through a rules
system that picks one best choice or reports an error.

> However, typedef does not provide the level of type safety one would
 > expect in a corresponding Ada program.

Typedef merely creates a synonym for a type, another name by which that
type is known. It cannot increase or decrease safety in any way, although
it may increase abstraction.