Re: [lmi] g++-12 valarray defect

[Greg Chicares]

On 8/17/22 00:40, Vadim Zeitlin wrote:
> On Wed, 17 Aug 2022 00:09:06 +0000 Greg Chicares <gchicares@sbcglobal.net> 
> wrote:
> 
> GC> Minimal reproducible test case:
[...]
>  I can confirm that I can reproduce the problem here too, just by adding
> -Walloc-zero and -O1 (or greater) flags to the compiler command line.
> 
>  Have you considered reporting this to gcc? I can't find any existing bug
> reports about this in their bug tracker.

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=106664

I presented a different case first:
    std::valarray<double> w {1};
    w.resize(0); // warns
because I found a couple of invalid reports of errors assigning
valarrays of incompatible sizes, and I wanted to guide them away
from thinking this was just another instance of that mistake.

I incorporated the insights you offered.

> GC> It also seems weird that the warning is given on a system header,
> GC> where I thought it would be disregarded. Maybe that's because
> GC> it's inlined.
> 
>  Yes, I guess this is the explanation. But it doesn't really help dealing
> with this warning, unfortunately.

I can deal with it pragmatically.