Macro field

macro_rules! field {
    (&gen $genref:tt $($field:tt)+) => { ... };
}

Maps a GenRef over field access and indexing.

Returns a GenRef to the field. Accessing nested fields is supported.

The receiver (the expression returning GenRef) must be a single token (an identifier) or it must be wrapped in parentheses.

Examples:

field!(&gen genref.field)
field!(&gen genref.field1.2.field3[4])
field!(&gen (obtain_genref()).field)
field!(&gen (container.genref).field)