Macro aerosol::parse_trait_def

macro_rules! parse_trait_def {
    {
        $caller:tt
        input = [{ $name:ident { $($body:tt)* } }]
    } => { ... };
    {
        $caller:tt
        input = [{ $name:ident: $($rest:tt)* }]
    } => { ... };
    {
        $caller:tt
        name = [{ $name:ident }]
        $(bound = [{ $($bound:tt)* }])*
        rest = [{ { $($body:tt)* } }]
    } => { ... };
}