On Wed, Jun 30, 2021 at 01:34:07PM -0400, Jeff King wrote:
> As an aside, having to have a separate bundle_header_init() and
> BUNDLE_HEADER_INIT is annoying (because they both must be kept up to
> date with each other), but quite common in our code base. I wonder if
> writing:
>
> void bundle_header_init(struct bundle_header *header)
> {
> struct bundle_header blank = BUNDLE_HEADER_INIT;
> memcpy(header, &blank, sizeof(*header));
> }
>
> would let a smart enough compiler just init "header" in place without
> the extra copy (the performance of a single bundle_header almost
> certainly doesn't matter, but it might for other types).
>
> Just musing. ;)
For my own curiosity, the answer is yes: https://godbolt.org/z/s54dc6ss9
With "gcc -O2" the memcpy goes away and we init "header" directly.
If we want to start using this technique widely, I don't think it should
be part of your series, though. This probably applies to quite a few
data structures, so it would make more sense to have a series which
converts several.
-Peff
