> the history of closures in Rust is a long and convoluted one, with many dead ends and failed experiments.

I desperately hope that someday, when all the dust settles, someone writes an account of this and other long and winding paths Rust has taken through its evolution, so people in the future can get the benefit of this wisdom. An account of dead ends could make for fascinating reading.

The trick would be putting in just the right amount of detail. Enough so the reader can truly understand the reasoning behind why things worked (or didn't) without being so dense as to be unreadable.