Generate the impl block via generate_trait_impl_text_from_impl

[0xPoe]

Try to close #8827

[0xPoe]

@Veykril Do you have any suggestions on how to get strukt right here? Thanks!

[Veykril]

Right this is a bit more annoying to do here. I think what we actually want here is another function generate_trait_impl_text_from_impl(impl_: &ast::Impl, trait_text: &str, code: &str) -> String instead which copies the generics and all from another impl instead.

As for the following example:

struct Foo<T> { t: T }

impl<T: From<i32>> Foo<T> {
    fn new() -> Self {
        Foo { t: 0.into() }
    }
}

Here we want the T: From<i32> bounds of the impl, not just the T from the struct def. So we don't actually need the struct def here, only the impl node.

It's fine to copy the generate_impl_text_inner impl for that for now so that there is also a version working for an ast::Impl, or edit it so that it works for both if you can.

[0xPoe]

@Veykril Added. Thanks for your help!

[Veykril]

bors r+

[bors]

Build succeeded:

• Rust (macos-latest)
• Rust (ubuntu-latest)
• Rust (windows-latest)
• TypeScript (ubuntu-latest)
• TypeScript (windows-latest)