/// 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>