Function extern_spec_T_Option_T_get_or_insert 

pub fn extern_spec_T_Option_T_get_or_insert<T>(
    self_: &mut Option<T>,
    value: T,
) -> &mut T

extern spec for Option<T>::get_or_insert

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

terminates

ghost

ensures

match *self {
    None => *result == value && ^self == Some(^result),
    Some(_) => *self == Some(*result) && ^self == Some(^result) && resolve(value),
}