src/tools/rust-analyzer/crates/stdx/src/non_empty_vec.rs

   1 //! See [`NonEmptyVec`].
   2
   3 /// A [`Vec`] that is guaranteed to at least contain one element.
   4 pub struct NonEmptyVec<T> {
   5     first: T,
   6     rest: Vec<T>,
   7 }
   8
   9 impl<T> NonEmptyVec<T> {
  10     #[inline]
  11     pub fn new(first: T) -> Self {
  12         NonEmptyVec { first, rest: Vec::new() }
  13     }
  14
  15     #[inline]
  16     pub fn last_mut(&mut self) -> &mut T {
  17         self.rest.last_mut().unwrap_or(&mut self.first)
  18     }
  19
  20     #[inline]
  21     pub fn pop(&mut self) -> Option<T> {
  22         self.rest.pop()
  23     }
  24
  25     #[inline]
  26     pub fn push(&mut self, value: T) {
  27         self.rest.push(value)
  28     }
  29
  30     #[inline]
  31     pub fn len(&self) -> usize {
  32         1 + self.rest.len()
  33     }
  34
  35     #[inline]
  36     pub fn into_last(mut self) -> T {
  37         self.rest.pop().unwrap_or(self.first)
  38     }
  39 }