Re: gnulib warnings when compiling Faddeeva.cc

[Steven G. Johnson]

On 12/14/12 1:25 PM, John W. Eaton wrote:
> On 13-Dec-2012, Steven G. Johnson wrote:
>
> | John W. Eaton wrote:
> |>  On 13-Dec-2012, Steven G. Johnson wrote:
> |>  | Except that there is no gnulib "cmath" header file as far as I can tell.
> |>
> |>  I think cmath includes math.h on most systems.  That may not be
> |>  required, but it's the way it works with GNU libstdc++ headers.
> |
> | Probably is more portable to include<math.h>  directly, since it can't
> | be guaranteed that cmath will #include math.h or that it will be
> | compatible with the gnulib one.
>
> I'd prefer to include cmath in C++ code.

The options are:

a) use ::floor, and accept the (innocuous) warning

b) use <cmath> and GNULIB_NAMESPACE::floor; this may be nonportable 
since it assumes that the system <cmath> header includes math.h and is 
compatible with the gnulib math.h

c) use <math.h> and GNULIB_NAMESPACE::floor; this should be portable 
since math.h is still in the C++ standard (despite being deprecated).

d) change gnulib to provide a <cmath> header and use (b); this may take 
some time, so in the meantime one needs to pick (a)-(c).

--SGJ