tbp <tbp...@gmail.com> writes:
> I could really use -Wdouble-promotion but, atm, it appears quite impractical,
> $ cat double.cc
> #include <cstdio>
> void foo(...);
> int main() {
> float f = 1;
> foo(f);
> printf("%f", f);
> }
> $ /usr/local/gcc-4.6-20100913/bin/g++ -Wdouble-promotion double.cc
> double.cc: In function 'int main()':
> double.cc:5:7: warning: implicit conversion from 'float' to 'double'
> when passing argument to function [-Wdouble-promotion]
> double.cc:6:16: warning: implicit conversion from 'float' to 'double'
> when passing argument to function [-Wdouble-promotion]
>
> ... and the interesting bits are lost in the noise. I can't think of a
> workaround.
> So i have to ask: Is that how it's meant to be, or simply a temporary
> shortcoming? Have i missed an obvious kludge?
This question is not appropriate for the mailing list g...@gcc.gnu.org.
It would be appropriate for gcc-h...@gcc.gnu.org. Please take any
followups to gcc-help. Thanks.
This is among the kinds of things which -Wdouble-promotion is documented
to warn about, so, yes, this is how it's meant to be. These are cases
where a float value is implicitly converted to a double value. Note
that the warning only applies to implicit conversions, so you can
silence it by adding explicit casts to double.
Ian
