[Review][PQS] Physical Quantities
Wonderful library! I hope it becomes part of boost. Even if we get 't1_?', how committed are you to providing 't2_?' and 't3_?'? Further, this may or not be the right place for this and I know you are big on the SI or similar units but has there been any consideration to adding monetary types. The requirements would be a monetary base class with specializations for dollars, pounds, euros and expandable to any type of currency. The further needs to be a global, static or facet, that is replaceable and stores the conversion factors that way it could have a default text file implementation that could be replaced with an database implementation.
"Jarrad Waterloo" wrote:
Wonderful library! I hope it becomes part of boost.
Thanks. (Maybe ... if it gets some more reviews ... (and positive) in the home stretch ... ).
Even if we get 't1_?', how committed are you to providing 't2_?' and 't3_?'?
t2 was in a previous version and it is useful, should go in. t3 would be a clumsy great beast, but would be useful for retrieving quantities from XML or passed as distributed objects: http://unitsml.nist.gov/
Further, this may or not be the right place for this and I know you are big on the SI or similar units but has there been any consideration to adding monetary types. The requirements would be a monetary base class with specializations for dollars, pounds, euros and expandable to any type of currency. The further needs to be a global, static or facet, that is replaceable and stores the conversion factors that way it could have a default text file implementation that could be replaced with an database implementation.
One reason the PQS cant handle money units is that their relationship isnt constant or even necessarily agreed upon by any two different authorities at one time. Physical quantities have nominally constant conversion factors. That impacts in the way the library can do a lot of computations at compile time. I know this issue comes up a lot. Why is money not a physical quantity. I dont really have an answer, except to say that I the SI dont consider money to be a physical quantity. There must also be a need for a type that works out (say) the cost of applying paint to a certain area. Its another field that PQS could be expanded into. The scope of that library is potentially very wide of course! regards Andy Little
"Andy Little" wrote:
Further, this may or not be the right place for this and I know you are big on the SI or similar units but has there been any consideration to adding monetary types. The requirements would be a monetary base class with specializations for dollars, pounds, euros and expandable to any type of currency. The further needs to be a global, static or facet, that is replaceable and stores the conversion factors that way it could have a default text file implementation that could be replaced with an database implementation.
One reason the PQS cant handle money units is that their relationship isnt constant or even necessarily agreed upon by any two different authorities at one time. Physical quantities have nominally constant conversion factors. That impacts in the way the library can do a lot of computations at compile time. I know this issue comes up a lot. Why is money not a physical quantity. I dont really have an answer, except to say that I the SI dont consider money to be a physical quantity.
There must also be a need for a type that works out (say) the cost of applying paint to a certain area. Its another field that PQS could be expanded into. The scope of that library is potentially very wide of course!
There was at least one massive thread about hypothetical boost::money library, year or so ago. My impression was that such tool could be potentionally something even larger than current pqs. /Pavel
participants (3)
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Andy Little -
Jarrad Waterloo -
Pavel Vozenilek