Macro aerosol::parse_bound

macro_rules! parse_bound {
    {
        $caller:tt
        input = [{ $($input:tt)* }]
    } => { ... };
    {
        $caller:tt
        $(bound = [{ $($bound:tt)* }])*
        rest = [{ $($rest:tt)* }]
    } => { ... };
    {
        $caller:tt
        $(bound = [{ $($bound:tt)* }])*
        type = [{ $($type:tt)* }]
        rest = [{ + $($rest:tt)* }]
    } => { ... };
    {
        $caller:tt
        $(bound = [{ $($bound:tt)* }])*
        type = [{ $($type:tt)* }]
        rest = [{ $($rest:tt)* }]
    } => { ... };
}