diff --git a/src/func/classes/effect.rs b/src/func/classes/effect.rs
index 760a431..e5f29f3 100644
--- a/src/func/classes/effect.rs
+++ b/src/func/classes/effect.rs
@@ -10,8 +10,8 @@ pub trait Effect {
 
 #[derive(Clone)]
 pub struct WithEffect<A, E> {
-    value: A,
-    effect: E,
+    pub value: A,
+    pub effect: E,
 }
 
 impl<A, E: Effect> WithEffect<A, E> {
diff --git a/src/testing/counted.rs b/src/testing/counted.rs
index da98c44..f718c25 100644
--- a/src/testing/counted.rs
+++ b/src/testing/counted.rs
@@ -22,188 +22,34 @@ impl Context for TestContextCounted {
     }
 }
 
-#[derive(CovariantFunctor)]
-pub struct CountedClass;
+pub type CountedClass = classes::effect::EffectClass<usize>;
 
-pub struct Counted<A> {
-    a: A,
-    n: usize,
-}
+impl classes::effect::Effect for usize {
+    fn pure() -> Self {
+        0
+    }
 
-trait WithCount: Sized {
-    fn with_count(self, n: usize) -> Counted<Self>;
-}
+    fn seq(lhs: Self, rhs: Self) -> Self {
+        max(lhs, rhs)
+    }
 
-impl<A> WithCount for A {
-    fn with_count(self, n: usize) -> Counted<Self> {
-        Counted { a: self, n }
+    fn after(self, effect: Self) -> Self {
+        self + effect
     }
 }
 
+pub type Counted<A> = classes::effect::WithEffect<A, usize>;
+
 impl<A> Counted<A> {
     fn add(self, n: usize) -> Self {
         Counted {
-            a: self.a,
-            n: self.n + n,
+            value: self.value,
+            effect: self.effect + n,
         }
     }
 
     pub fn count(&self) -> usize {
-        self.n
-    }
-}
-
-impl WeakFunctor for CountedClass {
-    type F<'a, A: 'a> = Counted<A>;
-}
-
-impl Functor for CountedClass {
-    fn fmap<'a, A: 'a, B: 'a>(f: impl 'a + FnOnce(A) -> B, fa: Self::F<'a, A>) -> Self::F<'a, B>
-    where
-        Self: 'a,
-    {
-        f(fa.a).with_count(fa.n)
-    }
-
-    fn replace<'a, A: 'a, B: 'a>(fa: Self::F<'a, A>, b: B) -> Self::F<'a, B>
-    where
-        Self: 'a,
-    {
-        b.with_count(fa.n)
-    }
-
-    fn void<'a, A: 'a>(fa: Self::F<'a, A>) -> Self::F<'a, ()>
-    where
-        Self: 'a,
-    {
-        ().with_count(fa.n)
-    }
-}
-
-impl Pure for CountedClass {
-    fn pure<'a, A: 'a>(a: A) -> Self::F<'a, A> {
-        a.with_count(0)
-    }
-}
-
-impl ApplicativeSeq for CountedClass {
-    fn seq<'a, A: 'a, B: 'a>(
-        ff: Self::F<'a, impl 'a + FnOnce(A) -> B>,
-        fa: Self::F<'a, A>,
-    ) -> Self::F<'a, B>
-    where
-        Self: 'a,
-    {
-        (ff.a)(fa.a).with_count(max(ff.n, fa.n))
-    }
-}
-
-impl ApplicativeLA2 for CountedClass {
-    fn la2<'a, A: 'a, B: 'a, C: 'a>(
-        f: impl 'a + FnOnce(A, B) -> C,
-        fa: Self::F<'a, A>,
-        fb: Self::F<'a, B>,
-    ) -> Self::F<'a, C>
-    where
-        Self: 'a,
-    {
-        f(fa.a, fb.a).with_count(max(fa.n, fb.n))
-    }
-}
-
-impl ApplicativeTuple for CountedClass {
-    fn tuple<'a, A: 'a, B: 'a>((fa, fb): (Self::F<'a, A>, Self::F<'a, B>)) -> Self::F<'a, (A, B)>
-    where
-        Self: 'a,
-    {
-        (fa.a, fb.a).with_count(max(fa.n, fb.n))
-    }
-}
-
-impl Applicative for CountedClass {
-    fn discard_first<'a, A: 'a, B: 'a>(fa: Self::F<'a, A>, fb: Self::F<'a, B>) -> Self::F<'a, B>
-    where
-        Self: 'a,
-    {
-        fb.a.with_count(max(fa.n, fb.n))
-    }
-
-    fn discard_second<'a, A: 'a, B: 'a>(fa: Self::F<'a, A>, fb: Self::F<'a, B>) -> Self::F<'a, A>
-    where
-        Self: 'a,
-    {
-        fa.a.with_count(max(fa.n, fb.n))
-    }
-}
-
-impl Monad for CountedClass {
-    fn bind<'a, A: 'a, B: 'a>(
-        fa: Self::F<'a, A>,
-        f: impl 'a + FnOnce(A) -> Self::F<'a, B>,
-    ) -> Self::F<'a, B>
-    where
-        Self: 'a,
-    {
-        f(fa.a).add(fa.n)
-    }
-
-    fn iterate_mut<'a, A: 'a, B: 'a>(
-        mut a: A,
-        mut f: impl 'a + FnMut(A) -> Self::F<'a, ControlFlow<B, A>>,
-    ) -> Self::F<'a, B>
-    where
-        Self: 'a,
-    {
-        let mut n = 0;
-        loop {
-            let fa = f(a);
-            n += fa.n;
-            match fa.a {
-                ControlFlow::Continue(next_a) => a = next_a,
-                ControlFlow::Break(b) => return b.with_count(n),
-            }
-        }
-    }
-
-    fn iterate_argument<'a, A: 'a, B: 'a>(
-        mut a: A,
-        mut f: impl AIterative<'a, T = Self, A = A, B = B>,
-    ) -> Self::F<'a, B>
-    where
-        Self: 'a,
-    {
-        let mut n = 0;
-        loop {
-            let fa = f.next(a);
-            n += fa.n;
-            match fa.a {
-                ControlFlow::Continue((next_a, next_f)) => (a, f) = (next_a, next_f),
-                ControlFlow::Break(b) => return b.with_count(n),
-            }
-        }
-    }
-
-    fn iterate<'a, B: 'a>(mut f: impl Iterative<'a, T = Self, B = B>) -> Self::F<'a, B>
-    where
-        Self: 'a,
-    {
-        let mut n = 0;
-        loop {
-            let fa = f.next();
-            n += fa.n;
-            match fa.a {
-                ControlFlow::Continue(next_f) => f = next_f,
-                ControlFlow::Break(b) => return b.with_count(n),
-            }
-        }
-    }
-
-    fn join<'a, A: 'a>(ffa: Self::F<'a, Self::F<'a, A>>) -> Self::F<'a, A>
-    where
-        Self::F<'a, A>: 'a,
-        Self: 'a,
-    {
-        ffa.a.add(ffa.n)
+        self.effect
     }
 }