Function extern_spec_T_Option_T_get_or_insert_default 

pub fn extern_spec_T_Option_T_get_or_insert_default<T>(
    self_: &mut Option<T>,
) -> &mut T
where
    T: Default,

extern spec for Option<T>::get_or_insert_default

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

requires

self

ensures

self