Macro serde::de::impls::num_as_self

macro_rules! num_as_self {
    ($ty:ident : $visit:ident) => { ... };
    (nonzero $primitive:ident $ty:ident : $visit:ident) => { ... };
    (saturating $primitive:ident $ty:ident : $visit:ident) => { ... };
}