Type Alias fmExprContextCallbackFunction 

pub type fmExprContextCallbackFunction = Option<unsafe extern "C-unwind" fn(arg: Datum)>;

Aliased Type

pub enum fmExprContextCallbackFunction {
    None,
    Some(unsafe extern "C-unwind" fn(Datum)),
}

Variants

None

No value.

Some(unsafe extern "C-unwind" fn(Datum))

Some value of type T.