Hi me22!!! :-) Scott McMurray (aka me22) wrote about boost::int_t<Bits>:
The implementation is quite ingenious, actually. On a proverbial toaster with 42-bit everything, a request for int_t<39>::least would give a signed char, the "smallest" type.
I agree about it being quite ingenious. And I like the fact that it supports 42-bit-everything-systems. But still, personally I'd rather have it support all kinds of 64-bits platforms...
Does Boost support ILP64 platforms? If so, I guess int_t<32>::least should select _int32, instead of int, on such a platform!
The current implementation deals only in standard C++98 types.
And should it stay that way?
Now I remember someone already already come up with a patch?
You can still find the patch in the mailing list archives: http://lists.boost.org/Archives/boost/2006/06/106262.php
I like your int_exact_t<Bits>::exact, Scott! It could really be of help, for my own Boost-based project. Still I don't like the fact that it will fail to get me a 32-bits integer (_int32) on an ILP64 platform. Why not having int_exact_t entirely based on the exact-width integer types from <boost/integer.hpp>? Actually I was thinking of a far more simple implementation, as follows. (In practice, I find it quite convenient to have the signed and the unsigned type grouped within one struct.) //////////////////////////////////////////////////////////// template <unsigned Bits> struct int_exact { }; template <> struct int_exact<8> { typedef int8_t signed_type; typedef uint8_t unsigned_type; }; template <> struct int_exact<16> { typedef int16_t signed_type; typedef uint16_t unsigned_type; }; template <> struct int_exact<32> { typedef int32_t signed_type; typedef uint32_t unsigned_type; }; #ifndef BOOST_NO_INT64_T template <> struct int_exact<64> { typedef int64_t signed_type; typedef uint64_t unsigned_type; }; #endif //////////////////////////////////////////////////////////// AFAIK, such a template would correctly support any 64-bits platform, including ILP64. What do you think? Anyway, if you would like to add ILP64 support to <boost/integer.hpp> in a different way, I would appreciate your solution as well... I just hope to see it soon, in a Boost release version! :-) Kind regards, Niels