Function ferrite_session::choose

pub fn choose<N, M, C, A, B, Row>(
    _: N, 
    _: M, 
    cont: PartialSession<N::Target, A>
) -> PartialSession<C, A> where
    C: Context,
    A: Protocol,
    B: Protocol,
    Row: RowCon,
    N: ContextLens<C, ExternalChoice<Row>, B>,
    M: Prism<Row, Elem = B>,