diff --git a/src/cache.rs b/src/cache.rs
index a64fd78..2d31a78 100644
--- a/src/cache.rs
+++ b/src/cache.rs
@@ -6,90 +6,3 @@ use std::{
 	ToOwned,
     },
 };
-
-pub trait Cache<T>
-{
-    fn cap(&self) -> Option<usize>;
-    fn len(&self) -> usize;
-    
-    fn insert(&mut self, value: T) -> &T;
-    fn get<Q: ?Sized + PartialEq<T>>(&self, value: &Q) -> Option<&T>;
-}
-
-pub struct MemCache<T>(Vec<T>);
-pub struct UnlimitedMemCache<T>(Vec<T>);
-
-impl<T> MemCache<T>
-{
-    /// Create a new cache with a max size
-    pub fn new(cap: usize) -> Self
-    {
-	Self(Vec::with_capacity(cap))
-    }
-}
-
-impl<T> Cache<T> for MemCache<T>
-{
-    fn cap(&self) -> Option<usize>
-    {
-	Some(self.0.capacity())
-    }
-    fn len(&self) -> usize
-    {
-	self.0.len()
-    }
-
-    fn insert(&mut self, value: T) -> &T
-    {
-	if self.0.len() == self.0.capacity() {
-	    self.0.remove(self.0.len()-1);
-	}
-	self.0.insert(0, value);
-	&self.0[0]
-    }
-    
-    fn get<Q: ?Sized + PartialEq<T>>(&self, value: &Q) -> Option<&T>
-    {
-	for x in self.0.iter() {
-	    if value.eq(x) {
-		return Some(x);
-	    }
-	}
-	None
-    }
-}
-
-impl<T> UnlimitedMemCache<T>
-{
-    /// Create a new cache
-    pub fn new() -> Self
-    {
-	Self(Vec::new())
-    }
-}
-
-// extension
-
-pub trait CacheExt<T>
-{
-    /// Insert into the cache if borrowed value is not present, 
-    fn clone_insert<'a, Q>(&'a mut self, refer: &Q) -> &'a T
-    where Q: ToOwned<Owned=T> + ?Sized + PartialEq<T>,
-	  T: Borrow<Q>;
-}
-
-impl<S, T> CacheExt<T> for S
-where S: Cache<T>,
-      T: Clone
-{
-    fn clone_insert<'a, Q>(&'a mut self, refer: &Q) -> &'a T
-    where Q: ToOwned<Owned=T> + ?Sized + PartialEq<T>,
-	  T: Borrow<Q>
-    {
-	if let Some(get) = self.get(refer) {
-	    return get;
-	}
-	
-	self.insert(refer.to_owned())
-    }
-}
diff --git a/src/main.rs b/src/main.rs
index dfa7d50..4c65412 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -12,10 +12,6 @@ mod bytes;
 mod suspend;
 
 mod cache;
-use cache::{
-    Cache,
-    CacheExt as _,
-};
 
 mod config;
 mod tripcode;