Re: [PATCH] Implement floordiv operator for gdb.Value

[Jonathan Wakely <jwakely at redhat dot com>]

On 20/09/16 17:35 +0100, Jonathan Wakely wrote:
> On 20/09/16 16:33 +0100, Pedro Alves wrote:
> > > @@ -1142,7 +1160,15 @@ valpy_binop_throw (enum valpy_opcode opcode, PyObject *self, PyObject *other)
> > >     }
> > >
> > >   if (res_val)
> > > -    result = value_to_value_object (res_val);
> > > +    {
> > > +      if (floor_it)
> > > +        {
> > > +          double d = value_as_double (res_val);
> >
> > Should be s/double/DOUBLEST, I suppose?
>
> OK - if I do that then floor(d) will convert it back to double,
> unless you #include <cmath> and using std::floor, so that the overload
> for long double is visible (in C++ <math.h> names like floor are
> overloaded so you don't need to use floorf/floor/floorl according to
> the type).

P.S. In theory it should work with <math.h> and without the
using-declaration, but with GCC that wasn't true until GCC 6.1 (see
http://developerblog.redhat.com/2016/02/29/why-cstdlib-is-more-complicated-than-you-might-think/
for the gory details).

So to get the right result for older versions of GCC you need <cmath>.