diff --git a/lib/runtime-core/src/structures/mono_vec.rs b/lib/runtime-core/src/structures/mono_vec.rs
deleted file mode 100644
index fe19d2510..000000000
--- a/lib/runtime-core/src/structures/mono_vec.rs
+++ /dev/null
@@ -1,85 +0,0 @@
-#[derive(Debug, Clone)]
-enum MonoVecInner<T> {
-    None,
-    Inline(T),
-    Heap(Vec<T>),
-}
-
-/// A type that can hold zero items,
-/// one item, or many items.
-#[derive(Debug, Clone)]
-pub struct MonoVec<T> {
-    inner: MonoVecInner<T>,
-}
-
-impl<T> MonoVec<T> {
-    pub fn new() -> Self {
-        Self {
-            inner: MonoVecInner::None,
-        }
-    }
-
-    pub fn new_inline(item: T) -> Self {
-        Self {
-            inner: MonoVecInner::Inline(item),
-        }
-    }
-
-    pub fn with_capacity(capacity: usize) -> Self {
-        match capacity {
-            0 | 1 => Self::new(),
-            _ => Self {
-                inner: MonoVecInner::Heap(Vec::with_capacity(capacity)),
-            },
-        }
-    }
-
-    pub fn push(&mut self, item: T) {
-        let uninit = MonoVecInner::None;
-        let prev = mem::replace(&mut self.inner, uninit);
-        let next = match prev {
-            MonoVecInner::None => MonoVecInner::Inline(item),
-            MonoVecInner::Inline(previous_item) => MonoVecInner::Heap(vec![previous_item, item]),
-            MonoVecInner::Heap(mut v) => {
-                v.push(item);
-                MonoVecInner::Heap(v)
-            }
-        };
-        let uninit = mem::replace(&mut self.inner, next);
-        mem::forget(uninit);
-    }
-
-    pub fn pop(&mut self) -> Option<T> {
-        match self.inner {
-            MonoVecInner::None => None,
-            MonoVecInner::Inline(ref mut item) => {
-                let uninit = unsafe { mem::zeroed() };
-                let item = mem::replace(item, uninit);
-                let uninit = mem::replace(&mut self.inner, MonoVecInner::None);
-                mem::forget(uninit);
-                Some(item)
-            }
-            MonoVecInner::Heap(ref mut v) => v.pop(),
-        }
-    }
-
-    pub fn as_slice(&self) -> &[T] {
-        match self.inner {
-            MonoVecInner::None => unsafe {
-                slice::from_raw_parts(mem::align_of::<T>() as *const T, 0)
-            },
-            MonoVecInner::Inline(ref item) => slice::from_ref(item),
-            MonoVecInner::Heap(ref v) => &v[..],
-        }
-    }
-
-    pub fn as_slice_mut(&mut self) -> &mut [T] {
-        match self.inner {
-            MonoVecInner::None => unsafe {
-                slice::from_raw_parts_mut(mem::align_of::<T>() as *mut T, 0)
-            },
-            MonoVecInner::Inline(ref mut item) => slice::from_mut(item),
-            MonoVecInner::Heap(ref mut v) => &mut v[..],
-        }
-    }
-}