Re: [boost] Re: Any interest in a decimal and money class?

From: Beman Dawes (bdawes_at_[hidden])
Date: 2005-01-09 19:32:22

At 04:50 PM 1/9/2005, Stefan Slapeta wrote:
 >Beman Dawes wrote:
 >>
 >> I asked on one of the committee reflectors, and the response was that
 >> the library IBM licenses isn't what is being standardized, so there is
 >> no issue. For C, what will be standardized are built-in data types, not 

 >> a library. For C++, what will be standardized may be a library, but it
 >> will be designed for C++.
 >
 > From a user's perspective, yes. Internally, the solution will be based
 >on the same C interface to enable any hardware support for the future, 
no?

It isn't clear yet. It is possible that C will treat the three decimal 
types as built-ins, while C++ will provide a library solution. That is 
probably unlikely, but at this early stage it is still possible. Bill 
Plauger is the point man for both C and C++ committees, and his thinking is 
given in:

http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2004/n1567.htm

Note that the operations available are not specified as a C interface, but 
rather in a metalanguage. See:

http://www2.hursley.ibm.com/decimal/decarith.pdf

That document also explains the rounding modes available, exceptions, etc.

 >> Sorry, I'm having trouble understanding your meaning. Are you saying in 

 >> effect that decimal types should have be standardized in C and C++ a
 >> long time ago?
 >>
 >
 >Yes, today there are some proposals for extensions that I bet are useful
 >for _much_ less people than a decimal data type would be.

Both C and C++ committees are committed to decimal arithmetic technical 
reports, so even though the details are as yet unclear, it is probable that 
the two languages will get decimal arithmetic. A case of better late than 
never, I suppose.

--Beman