Implement Extend for Vec

[schneiderfelipe]

I would like to implement Extend<&'a #name> for #vec_name as well (just like std::vec::Vec<T>), but I would have to make sure #name is Copy (where #name: Copy does not help).

This is not the most performant implementation either, but it works.

Fix #51.

[Luthaf]

I would like to implement Extend<&'a #name> for #vec_name

Maybe you can use the same kind of trick with higher-rank bounds as to_owned?

soa-derive/soa-derive-internal/src/refs.rs

Lines 150 to 153 in f41eecb

	pub fn to_owned(&self) -> #name
	// only expose to_owned is all fields are Clone
	// https://github.com/rust-lang/rust/issues/48214#issuecomment-1150463333
	where #( for<'b> #fields_types: Clone, )*

It would only check if all fields are copy and not the full struct, but this should be close enough.

[schneiderfelipe]

I would like to implement Extend<&'a #name> for #vec_name

Maybe you can use the same kind of trick with higher-rank bounds as to_owned?

soa-derive/soa-derive-internal/src/refs.rs

Lines 150 to 153 in f41eecb

	pub fn to_owned(&self) -> #name
	// only expose to_owned is all fields are Clone
	// https://github.com/rust-lang/rust/issues/48214#issuecomment-1150463333
	where #( for<'b> #fields_types: Clone, )*

It would only check if all fields are copy and not the full struct, but this should be close enough.

This did the trick. Now we have both impl Extend<#name> for #vec_name and impl<'a> Extend<#ref_name<'a>> for #vec_name, the last one only available if all fields are Clone, so that to_owned can be called. This matches the available implementations on Vec<T>, impl<T, A> Extend<T> for Vec<T, A> and impl<'a, T, A> Extend<&'a T> for Vec<T, A>.

[Luthaf]

This and #63 have been released on crates.io as soa-derive-internal==0.13.2