clown

An approximation of "capture-by-clone" lambdas in Rust.
Requires nightly and #![feature(proc_macro_hygiene, stmt_expr_attributes)]

Turns this: ```rust

[clown] || do_call(honk!(foo.bar))

into this: rust { let honk0 = (foo.bar).clone(); move || docall(honk_0) } ```