Macro strfmt::strfmt_builder

macro_rules! strfmt_builder {
    ($vars:expr,$value:expr) => { ... };
    ($vars:expr,$name:ident => $value:expr) => { ... };
    ($vars:expr,$value:expr,$($values:tt)*) => { ... };
    ($vars:expr,$name:ident => $value:expr,$($values:tt)*) => { ... };
}