Hi,
Quoting the docs for boost::numeric_cast: "There are several situations
where conversions are unsafe: [...] Conversions from floating point types
to integral types."
What about conversions from integral types to floating point types? E.g.
from 64bit int to double.
The following example shows what I mean:
#include <iostream>
#include <cmath>
#include
int main()
{
const uint64_t i = 123445678911188878;
std::cout << "i=" << i << std::endl;
const double d = i;
std::cout << "d=" << std::fixed << d << std::endl;
std::cout << "next=" << std::fixed << std::nextafter(d,
std::numeric_limits<double>::max() ) << std::endl;
std::cout << "prev=" << std::fixed << std::nextafter(d,
-std::numeric_limits<double>::max()) << std::endl;
// I'd expect the following cast to fail
const double dd = boost::numeric_cast<double>(i);
std::cout <<"dd=" << std::fixed << dd << std::endl;
return 0;
}
prints
i=123445678911188878
d=123445678911188880.000000
next=123445678911188896.000000
prev=123445678911188864.000000
dd=123445678911188880.000000
because that integer cannot be represented in double precision
Is there something in Boost to help here?
Thanks in advance
