Re: [boost] [shifted_ptr] "new shifted<T>"

From: Simonson, Lucanus J (lucanus.j.simonson_at_[hidden])
Date: 2008-06-06 18:05:22

Phil Bouchard wrote:
>Y:/UNIX/local/bin/../lib/gcc/mingw32/3.4.5/
>../../../../include/boost/numeric>/interval/checking.hpp:62: 
>error: invalid static_cast from type `int' to type `void*'

This is line 62 of checking.hpp:

std::numeric_limits<T>::quiet_NaN() : static_cast<T>(1));

It looks like we are casting a constant integer to void*, which it
doesn't like.  Obviously we could force the compiler to eat the line by
changing static_cast to reinterpret_cast, but that isn't good.  

Instead of casting to an integer constant, we could construct a T from
the integer constant:

std::numeric_limits<T>::quiet_NaN() : T(1));

, which seems like a reasonable thing to do.  I don't know why they use
static_cast instead, but there must have been a reason.  It looks like
there are numerous places in interval that need to be modified where
constants are being static_cast to T that prevent it from compiling for
intervals of pointer type.  I think intervals of pointer type make a lot
of sense.  In fact, it moves us in the direction of intervals of random
access iterators, which is sort of intriguing.  I guess its up to you to
make the case for a code change in interval to accommodate your use
case.

Luke