Function spare_capacity

src/buffer.rs:266–275

(v: &'a mut Vec<T>)

#[cfg(feature = "alloc")]
#[cfg_attr(docsrs, doc(cfg(feature = "alloc")))]
pub fn spare_capacity<'a, T>(v: &'a mut Vec<T>) -> SpareCapacity<'a, T> {
    debug_assert_ne!(
        v.capacity(),
        0,
        "`extend` uses spare capacity, and never allocates new memory, so the `Vec` passed to it \
         should have some spare capacity."
    );

    SpareCapacity(v)
}

#[cfg(feature = "alloc")]
impl<'a, T> private::Sealed<T> for SpareCapacity<'a, T> {