Unwarranted old-style cast warning and non-critical error

[Daniel J Sebald]

When building Octave, gcc issues this old-style cast warning:

In file included from builtins.cc:9:0:
../../octave/src/interpfcn/variables.h:105:40: warning: use of old-style 
cast
../../octave/src/interpfcn/variables.h:105:65: warning: use of old-style 
cast

It is due to the following line of code, and in particular the DBL_MIN 
and DBL_MAX:

extern OCTINTERP_API octave_value
set_internal_variable (double& var, const octave_value_list& args,
                       int nargout, const char *nm,
                       double minval = DBL_MIN, double maxval = DBL_MAX);

I think this may be a gcc compiler oversight.  I read somewhere that the 
warning went away with gcc version 4.5.0-5, but I have version 4.5.1 
(from late 2010) and I'm still getting the warning.

I tried to get rid of the warning with "static_cast<double>(DBL_MIN)" 
but that did not help.

Can someone please confirm this warning disappeared somewhere along the 
way in the last year and a half?

...

This leads to a question.  Is the line above intended instead to be the 
following (i.e., replace DBL_MIN with -DBL_MAX)?

extern OCTINTERP_API octave_value
set_internal_variable (double& var, const octave_value_list& args,
                       int nargout, const char *nm,
                       double minval = -DBL_MAX, double maxval = DBL_MAX);

I'm assuming that the default definitions are meant to be that there is 
no restriction on the value, as with the integer case defined before the 
double case:

extern OCTINTERP_API octave_value
set_internal_variable (int& var, const octave_value_list& args,
                       int nargout, const char *nm,
                       int minval = INT_MIN, int maxval = INT_MAX);

However, INT_MIN and DBL_MIN are not analogous.  DBL_MIN is the smallest 
positive double value (i.e., greater than zero).  I printed out the value:

DBL_MIN = 2.22507e-308

If the minval is meant to be -DBL_MAX, apparently this doesn't make a 
difference in behavior, otherwise a bug would have shown up long ago.

Dan