Macro batch_impl_name 

batch_impl_name!() { /* proc-macro */ }

Documentation placeholder for the #name{body} fill-by-name directive.

#name{body} looks up the single trait item named name — a method, an associated const, or an associated type — and fills it with body (the body must match that item’s shape).

#[batch_impl(Box<Vec<u32>> #count{self.len()})]
trait L { fn count(&self) -> usize; }

Documentation marker only — never call this function.