Re: A dozen unused return value warnings

[Hans-Bernhard B. <HBB...@t-...>]

Am 29.03.2017 um 21:01 schrieb Daniel J Sebald:
> On my system, configuration results in the unused return variable flag
> being set.  Attached is a diff file with code changes to get rid of
> those warnings.

Doing the change like that is just wrong:

> -    freopen("/dev/null","w",stdout);
> -    freopen("/dev/null","w",stderr);
> +    if (freopen("/dev/null","w",stdout));
> +    if (freopen("/dev/null","w",stderr));

The usual, widely accepted way of doing that is to cast an unused return 
value to (void), i.e.:

    (void)freopen("/dev/null","w",stdout);
    (void)freopen("/dev/null","w",stderr);

> Should the above really be included in Qt?  I don't think that Qt C++
> files need to use FPRINTF() any more for debugging.

That doesn't help with debugging non-QT, non-C++ files in gnuplot at 
all, though.

> Qt has it's own
> messaging system:

That's nice to know, but doesn't help us much, because we still want to 
be able to work _without_ any Qt involved, too.