/// Ensures that the entry is occupied by inserting the the result of the
/// given function if it is vacant.
///
/// Returns a mutable reference to the entry's value.
Ensures that the entry is occupied by inserting the the result of the
given function if it is vacant.

Returns a mutable reference to the entry's value.
Ensures that the entry is occupied by inserting the the result of the given function if it is vacant . Returns a mutable reference to the entry ' s value .
pub fn or_insert_with<F: FnOnce() -> V>(self, default: F) -> &'a mut V {
        match self {
            Occupied(entry) => entry.into_mut(),
            Vacant(entry) => entry.insert(default()),
        }
    }
pub fn or_insert_with < F : FnOnce ( ) -> V > ( self , default : F ) -> & ' a mut V { match self { Occupied ( entry ) => entry . into_mut ( ) , Vacant ( entry ) => entry . insert ( default ( ) ) , } }
Ensures that the entry is occupied by inserting the the result of the
given function if it is vacant.
Ensures that the entry is occupied by inserting the the result of the given function if it is vacant .
self
<not_specific>
default
F
<not_specific>