Macro map_impl

macro_rules! map_impl {
    (
        $(#[$attr:meta])*
        $ty:ident <K $(: $kbound1:ident $(+ $kbound2:ident)*)*, V $(, $typaram:ident : $bound1:ident $(+ $bound2:ident)*)*>,
        $access:ident,
        $with_capacity:expr,
    ) => { ... };
}