Re: [boost] Feature request for integer.hpp

From: Beman Dawes (bdawes_at_[hidden])
Date: 2002-05-15 10:38:30

At 01:20 AM 5/15/2002, Daryle Walker wrote:
 >on 5/1/02 2:54 PM, David Seidman at david_i_seidman_at_[hidden] wrote:
 >
 >> I require support for 64-bit integers in integer.hpp.
 >> I am using boost::int_t< numbits >::least, and I find
 >> that the 0 and 5 specializations for template
 >> int_least_helper are not implemented.  When is this
 >> support going to be added?
 >>
 >> BTW, this library works beautifully up to 32 bits.
 >
 >The lack of specializations for 0 and 5 are deliberate; we have to trap
 >requests larger than a "long" somehow.  To get a "long long," we would 
have
 >to conditionally widen the non-implementation gaps.  Also, some libraries
 >(like CRC) use these types for value-based template parameters, and there 

 >is
 >no guarantee that "long long" can be used that way.
 >
 >(You're also assuming the popular mapping 64 bits -> "long long" because 
32
 >bits -> "int" and "long".  A compiler could shift "long" to a 64-bit 
type.)

IIRC, at least one commercial compiler does in fact use "long" as a 64-bit 
type.  It allowed them to supply a compiler that was both standard 
conforming and supported 64-bit arithmetic years before "long long" was a 
possibility.

--Beman