Macro delete 

macro_rules! delete {
    ($m:expr, $k:expr) => { ... };
}

delete!(m, k) — Go’s delete(m, k) builtin for maps.

delete!(m, “key”) // &str literal — works directly delete!(m, &my_string) // owned String — pass & (HashMap.remove takes &Q) delete!(m, &42) // owned int — same

Silent no-op if the key isn’t present (matches Go).