Function extern_spec_T_Option_T_map_or 

pub fn extern_spec_T_Option_T_map_or<T, U, F: FnOnce(T) -> U>(
    self_: Option<T>,
    default: U,
    f: F,
) -> U

extern spec for Option<T>::map_or

This is not a real function: its only use is for documentation.

requires

match self { None => true, Some(t) => f.precondition((t,)) }

ensures

match self {
    None => result == default,
    Some(t) => f.postcondition_once((t,), result)
}