From: Andy Little (andy_at_[hidden])
Date: 2006-05-16 05:33:28
"Gerhard Wesp" wrote
> Physics gives quite clear directions as to which operations a time type
> must support:
> - Addidtion, subtraction, comparison with other time's.
> - Division by other time's to give a dimensionless type.
> - Conversion to/from whatever is useful, maybe stream operators.
> Note that any builtin arithmetic types support those operations, but
> they're not "typesafe" in the sense that you might end up e.g. adding
> time and length. A user-defined type can protect you from those
> accidents by only defining the above mentioned operations.
> *If* we want a user-defined type to represent time, it may well be part
> of a general framework for physical quantities. See e.g.
> section 6 for ideas on how this can be done.
BTW It might be useful to point out that my Physical Quantities library 'pqs' ,
which provides the above operations, is up for Formal Review by Boost at some
time in the near future:
(I hope that 'pqs_3_1_0' in that directory will be the review version, but that
will be subject to my Review Managers approval. If all is in order then I hope
that the review dates for pqs will be confirmed soon).
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