https://gcc.gnu.org/bugzilla/show_bug.cgi?id=115581
--- Comment #4 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
(In reply to Barnabás Pőcze from comment #3)
> Isn't your testcase a bit different? I guess my question is, why does gcc
> feel the need to make a local copy of a by-value argument when calling a
> function with a reference to it, but seemingly only in a function generated
> from a lambda?
No my testcase is exactly what is done when converting a lambda to a function
pointer. That is it creates a function which then calls the lamdba.
Just like this:
```
struct thing {
int x[64];
};
void f10(thing x)
{
auto l = [](thing x) {
g(x);
};
l(x);
}
auto *f13 = f10;
```
Which has still has the extra copy even for clang.
That is why I mentioned that clang seems to have a front-end optimization which
removes the copy when converting the lambda to a function pointer.
