ext improv

Cargo.lock

@@ -1028,6 +1028,15 @@ version = "0.4.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "c111b5bd5695e56cffe5129854aa230b39c93a305372fdbb2668ca2394eea9f8"
 
+[[package]]
+name = "smallvec"
+version = "1.6.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "1a55ca5f3b68e41c979bf8c46a6f1da892ca4db8f94023ce0bd32407573b1ac0"
+dependencies = [
+ "serde",
+]
+
 [[package]]
 name = "socket2"
 version = "0.3.19"
@@ -1393,6 +1402,7 @@ dependencies = [
  "difference",
  "futures",
  "serde",
+ "smallvec",
  "tokio",
  "warp",
 ]

Cargo.toml

@@ -5,9 +5,15 @@ version = "0.1.0"
 authors = ["Avril <flanchan@cumallover.me>"]
 edition = "2018"
 
+[features]
+default = ["nightly"]
+
+nightly = ["smallvec/const_generics"]
+
 [dependencies]
 difference = "2.0.0"
 futures = "0.3.8"
 serde = {version = "1.0.118", features=["derive"]}
+smallvec = {version = "1.6.0", features= ["union", "serde", "write"]}
 tokio = {version = "0.2", features=["full"] } 
 warp = "0.2.5"

src/delta.rs

@@ -160,7 +160,7 @@ impl Delta
 	    },
 	    DeltaKind::Clear => inserter.clear(),
 	    DeltaKind::Truncate => inserter.truncate(self.location),
-	    DeltaKind::Shift => ((),inserter.drain(..self.location)).0,
+	    DeltaKind::Shift => drop(inserter.drain(..self.location)),
 	}
     }
 }

src/ext.rs

@@ -4,6 +4,7 @@ use std::{
     fmt,
     ops,
 };
+use smallvec::SmallVec;
 
 /// Wrapper to derive debug for types that don't implement it.
 #[repr(transparent)]
@@ -83,6 +84,15 @@ impl<T> BackInserter<T> for Vec<T>
     }
 }
 
+impl<T> BackInserter<T> for SmallVec<T>
+    where T: smallvec::Array<Item = T>
+{
+    #[inline] fn push_back(&mut self, value: T)
+    {
+	self.push(value)
+    }
+}
+
 /// Absracts a closure for `BackInserter<T>`.
 pub struct BackInsertPass<T,F>(F, PhantomData<T>)
 where F: FnMut(T);
@@ -140,6 +150,14 @@ where T: BackInserter<T>
     }
 }
 
+impl<T> BackInserter<T> for Option<T>
+{
+    fn push_back(&mut self, value: T)
+    {
+	*self = Some(value);
+    }
+}
+
 pub trait VecExt<T>
 {
     /// Insert many elements with exact size iterator
@@ -290,7 +308,7 @@ mod tests
 	assert_eq!(&vec[..], &vec2[..]);
     }
     
-    #[cfg(nightly)]
+    #[cfg(feature="nightly")]
     mod benchmatks
     {
 	use super::super::*;

src/main.rs

@@ -1,6 +1,8 @@
+#![cfg_attr(feature="nightly", feature(test))] 
 
 #![allow(dead_code)]
 
+#[cfg(all(feature="nightly", test))] extern crate test; 
 #[macro_use] extern crate serde;
 
 #[macro_use] mod ext; use ext::*;