bendns' repos / rust-analyzer
Unnamed repository; edit this file 'description' to name the repository.
Diffstat (limited to 'crates/stdx/src/non_empty_vec.rs')
-rw-r--r--crates/stdx/src/non_empty_vec.rs45
1 files changed, 45 insertions, 0 deletions
diff --git a/crates/stdx/src/non_empty_vec.rs b/crates/stdx/src/non_empty_vec.rs
new file mode 100644
index 0000000000..199ee18b94
--- /dev/null
+++ b/crates/stdx/src/non_empty_vec.rs
@@ -0,0 +1,45 @@
+//! A [`Vec`] that is guaranteed to at least contain one element.
+
+pub struct NonEmptyVec<T>(Vec<T>);
+
+impl<T> NonEmptyVec<T> {
+ #[inline]
+ pub fn new(initial: T) -> Self {
+ NonEmptyVec(vec![initial])
+ }
+
+ #[inline]
+ pub fn last_mut(&mut self) -> &mut T {
+ match self.0.last_mut() {
+ Some(it) => it,
+ None => unreachable!(),
+ }
+ }
+
+ #[inline]
+ pub fn pop(&mut self) -> Option<T> {
+ if self.0.len() <= 1 {
+ None
+ } else {
+ self.0.pop()
+ }
+ }
+
+ #[inline]
+ pub fn push(&mut self, value: T) {
+ self.0.push(value)
+ }
+
+ #[inline]
+ pub fn len(&self) -> usize {
+ self.0.len()
+ }
+
+ #[inline]
+ pub fn into_first(mut self) -> T {
+ match self.0.pop() {
+ Some(it) => it,
+ None => unreachable!(),
+ }
+ }
+}