diff --git a/src/test/compile-fail/borrowck-overloaded-call.rs b/src/test/compile-fail/borrowck-overloaded-call.rs
index 7d35a27c0ae2..04d73cc36f04 100644
--- a/src/test/compile-fail/borrowck-overloaded-call.rs
+++ b/src/test/compile-fail/borrowck-overloaded-call.rs
@@ -17,7 +17,9 @@ struct SFn {
     y: isize,
 }
 
-impl Fn<(isize,),isize> for SFn {
+impl Fn<(isize,)> for SFn {
+    type Output = isize;
+
     extern "rust-call" fn call(&self, (z,): (isize,)) -> isize {
         self.x * self.y * z
     }
@@ -28,7 +30,9 @@ struct SFnMut {
     y: isize,
 }
 
-impl FnMut<(isize,),isize> for SFnMut {
+impl FnMut<(isize,)> for SFnMut {
+    type Output = isize;
+
     extern "rust-call" fn call_mut(&mut self, (z,): (isize,)) -> isize {
         self.x * self.y * z
     }
@@ -38,7 +42,9 @@ struct SFnOnce {
     x: String,
 }
 
-impl FnOnce<(String,),usize> for SFnOnce {
+impl FnOnce<(String,)> for SFnOnce {
+    type Output = usize;
+
     extern "rust-call" fn call_once(self, (z,): (String,)) -> usize {
         self.x.len() + z.len()
     }
diff --git a/src/test/compile-fail/extern-wrong-value-type.rs b/src/test/compile-fail/extern-wrong-value-type.rs
index d7586af291e8..db3373ea0277 100644
--- a/src/test/compile-fail/extern-wrong-value-type.rs
+++ b/src/test/compile-fail/extern-wrong-value-type.rs
@@ -16,5 +16,7 @@ fn is_fn<F>(_: F) where F: Fn() {}
 fn main() {
     // extern functions are extern "C" fn
     let _x: extern "C" fn() = f; // OK
-    is_fn(f); //~ ERROR the trait `core::ops::Fn()` is not implemented for the type `extern "C" fn()
+    is_fn(f);
+    //~^ ERROR the trait `core::ops::Fn<()>` is not implemented for the type `extern "C" fn()
+    //~| ERROR the trait `core::ops::Fn<()>` is not implemented for the type `extern "C" fn()
 }
diff --git a/src/test/compile-fail/feature-gate-unboxed-closures-manual-impls.rs b/src/test/compile-fail/feature-gate-unboxed-closures-manual-impls.rs
index cdb207f705f5..e5e5ddadafcc 100644
--- a/src/test/compile-fail/feature-gate-unboxed-closures-manual-impls.rs
+++ b/src/test/compile-fail/feature-gate-unboxed-closures-manual-impls.rs
@@ -8,18 +8,38 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
+// Test that manual impls of the `Fn` traits are not possible without
+// a feature gate. In fact, the specialized check for these cases
+// never triggers (yet), because they encounter other problems around
+// angle bracket vs parentheses notation.
+
 #![allow(dead_code)]
 
 struct Foo;
-impl Fn() for Foo { //~ ERROR manual implementations of `Fn` are experimental
+impl Fn<()> for Foo {
+    //~^ ERROR angle-bracket notation is not stable when used with the `Fn` family of traits
+    type Output = ();
+
+    extern "rust-call" fn call(&self, args: ()) -> () {}
+}
+struct Foo1;
+impl Fn() for Foo1 {
+    //~^ ERROR associated type bindings are not allowed here
+
     extern "rust-call" fn call(&self, args: ()) -> () {}
 }
 struct Bar;
-impl FnMut() for Bar { //~ ERROR manual implementations of `FnMut` are experimental
+impl FnMut<()> for Bar {
+    //~^ ERROR angle-bracket notation is not stable when used with the `Fn` family of traits
+    type Output = ();
+
     extern "rust-call" fn call_mut(&self, args: ()) -> () {}
 }
 struct Baz;
-impl FnOnce() for Baz { //~ ERROR manual implementations of `FnOnce` are experimental
+impl FnOnce<()> for Baz {
+    //~^ ERROR angle-bracket notation is not stable when used with the `Fn` family of traits
+    type Output = ();
+
     extern "rust-call" fn call_once(&self, args: ()) -> () {}
 }
 
diff --git a/src/test/compile-fail/fn-trait-formatting.rs b/src/test/compile-fail/fn-trait-formatting.rs
index f19e27640cbc..460e05c8438c 100644
--- a/src/test/compile-fail/fn-trait-formatting.rs
+++ b/src/test/compile-fail/fn-trait-formatting.rs
@@ -34,5 +34,7 @@ fn main() {
     //~| expected ()
     //~| found box
 
-    needs_fn(1is); //~ ERROR `core::ops::Fn(isize) -> isize`
+    needs_fn(1is);
+    //~^ ERROR `core::ops::Fn<(isize,)>`
+    //~| ERROR `core::ops::Fn<(isize,)>`
 }
diff --git a/src/test/compile-fail/issue-15094.rs b/src/test/compile-fail/issue-15094.rs
index 2c03a9e07332..977586483b03 100644
--- a/src/test/compile-fail/issue-15094.rs
+++ b/src/test/compile-fail/issue-15094.rs
@@ -16,7 +16,9 @@ struct Debuger<T> {
     x: T
 }
 
-impl<T: fmt::Debug> ops::Fn<(), ()> for Debuger<T> {
+impl<T: fmt::Debug> ops::Fn<(),> for Debuger<T> {
+    type Output = ();
+
     fn call(&self, _args: ()) {
 //~^ ERROR `call` has an incompatible type for trait: expected "rust-call" fn, found "Rust" fn
         println!("{:?}", self.x);
diff --git a/src/test/compile-fail/issue-17545.rs b/src/test/compile-fail/issue-17545.rs
index 0501a3013ccd..84800218efc9 100644
--- a/src/test/compile-fail/issue-17545.rs
+++ b/src/test/compile-fail/issue-17545.rs
@@ -10,7 +10,7 @@
 
 #![feature(unboxed_closures)]
 
-pub fn foo<'a, F: Fn<(&'a (),), ()>>(bar: F) {
+pub fn foo<'a, F: Fn(&'a ())>(bar: F) {
     bar.call((
         &(), //~ ERROR borrowed value does not live long enough
     ));
diff --git a/src/test/compile-fail/overloaded-calls-bad.rs b/src/test/compile-fail/overloaded-calls-bad.rs
index d784ba2d0d6b..61752e62abde 100644
--- a/src/test/compile-fail/overloaded-calls-bad.rs
+++ b/src/test/compile-fail/overloaded-calls-bad.rs
@@ -17,7 +17,9 @@ struct S {
     y: isize,
 }
 
-impl FnMut<(isize,),isize> for S {
+impl FnMut<(isize,)> for S {
+    type Output = isize;
+
     extern "rust-call" fn call_mut(&mut self, (z,): (isize,)) -> isize {
         self.x * self.y * z
     }
diff --git a/src/test/compile-fail/overloaded-calls-nontuple.rs b/src/test/compile-fail/overloaded-calls-nontuple.rs
index c06ab04cd849..41ecf7146138 100644
--- a/src/test/compile-fail/overloaded-calls-nontuple.rs
+++ b/src/test/compile-fail/overloaded-calls-nontuple.rs
@@ -17,7 +17,8 @@ struct S {
     y: isize,
 }
 
-impl FnMut<isize,isize> for S {
+impl FnMut<isize> for S {
+    type Output = isize;
     extern "rust-call" fn call_mut(&mut self, z: isize) -> isize {
         self.x + self.y + z
     }
diff --git a/src/test/compile-fail/regions-infer-invariance-due-to-mutability-4.rs b/src/test/compile-fail/regions-infer-invariance-due-to-mutability-4.rs
index 2e634dfe3eb6..2a246124f6f9 100644
--- a/src/test/compile-fail/regions-infer-invariance-due-to-mutability-4.rs
+++ b/src/test/compile-fail/regions-infer-invariance-due-to-mutability-4.rs
@@ -9,15 +9,15 @@
 // except according to those terms.
 
 
-struct invariant<'a> {
+struct Invariant<'a> {
     f: Box<for<'b> FnOnce() -> &'b mut &'a isize + 'static>,
 }
 
-fn to_same_lifetime<'r>(bi: invariant<'r>) {
-    let bj: invariant<'r> = bi;
+fn to_same_lifetime<'r>(bi: Invariant<'r>) {
+    let bj: Invariant<'r> = bi;
 }
 
-fn to_longer_lifetime<'r>(bi: invariant<'r>) -> invariant<'static> {
+fn to_longer_lifetime<'r>(bi: Invariant<'r>) -> Invariant<'static> {
     bi //~ ERROR mismatched types
 }
 
diff --git a/src/test/compile-fail/unboxed-closure-feature-gate.rs b/src/test/compile-fail/unboxed-closure-feature-gate.rs
index 5eb67a9bb71d..3536244f0116 100644
--- a/src/test/compile-fail/unboxed-closure-feature-gate.rs
+++ b/src/test/compile-fail/unboxed-closure-feature-gate.rs
@@ -11,7 +11,8 @@
 // Check that parenthetical notation is feature-gated except with the
 // `Fn` traits.
 
-trait Foo<A,R> {
+trait Foo<A> {
+    type Output;
 }
 
 fn main() {
diff --git a/src/test/compile-fail/unboxed-closure-sugar-default.rs b/src/test/compile-fail/unboxed-closure-sugar-default.rs
index 0d9e406b0867..870377bc1add 100644
--- a/src/test/compile-fail/unboxed-closure-sugar-default.rs
+++ b/src/test/compile-fail/unboxed-closure-sugar-default.rs
@@ -14,8 +14,9 @@
 #![feature(unboxed_closures)]
 #![allow(dead_code)]
 
-trait Foo<T,U,V=T> {
-    fn dummy(&self, t: T, u: U, v: V);
+trait Foo<T,V=T> {
+    type Output;
+    fn dummy(&self, t: T, v: V);
 }
 
 trait Eq<X: ?Sized> { }
@@ -24,14 +25,14 @@ fn eq<A: ?Sized,B: ?Sized>() where A : Eq<B> { }
 
 fn test<'a,'b>() {
     // Parens are equivalent to omitting default in angle.
-    eq::< Foo<(isize,),()>,               Foo(isize)                      >();
+    eq::< Foo<(isize,),Output=()>,                   Foo(isize)                      >();
 
     // In angle version, we supply something other than the default
-    eq::< Foo<(isize,),(),isize>,           Foo(isize)                      >();
+    eq::< Foo<(isize,),isize,Output=()>,      Foo(isize)                      >();
     //~^ ERROR not implemented
 
     // Supply default explicitly.
-    eq::< Foo<(isize,),(),(isize,)>,        Foo(isize)                      >();
+    eq::< Foo<(isize,),(isize,),Output=()>,   Foo(isize)                      >();
 }
 
 fn main() { }
diff --git a/src/test/compile-fail/unboxed-closure-sugar-equiv.rs b/src/test/compile-fail/unboxed-closure-sugar-equiv.rs
index 9dff0e9e01e3..dc5576aee650 100644
--- a/src/test/compile-fail/unboxed-closure-sugar-equiv.rs
+++ b/src/test/compile-fail/unboxed-closure-sugar-equiv.rs
@@ -16,8 +16,9 @@
 #![feature(unboxed_closures)]
 #![allow(dead_code)]
 
-trait Foo<T,U> {
-    fn dummy(&self, t: T, u: U);
+trait Foo<T> {
+    type Output;
+    fn dummy(&self, t: T, u: Self::Output);
 }
 
 trait Eq<X: ?Sized> { }
@@ -26,31 +27,32 @@ fn eq<A: ?Sized,B: ?Sized +Eq<A>>() { }
 
 fn test<'a,'b>() {
     // No errors expected:
-    eq::< Foo<(),()>,                   Foo()                         >();
-    eq::< Foo<(isize,),()>,               Foo(isize)                      >();
-    eq::< Foo<(isize,usize),()>,           Foo(isize,usize)                 >();
-    eq::< Foo<(isize,usize),usize>,         Foo(isize,usize) -> usize         >();
-    eq::< Foo<(&'a isize,&'b usize),usize>, Foo(&'a isize,&'b usize) -> usize >();
+    eq::< Foo<(),Output=()>,                       Foo()                         >();
+    eq::< Foo<(isize,),Output=()>,                 Foo(isize)                      >();
+    eq::< Foo<(isize,usize),Output=()>,            Foo(isize,usize)                 >();
+    eq::< Foo<(isize,usize),Output=usize>,         Foo(isize,usize) -> usize         >();
+    eq::< Foo<(&'a isize,&'b usize),Output=usize>, Foo(&'a isize,&'b usize) -> usize >();
 
     // Test that anonymous regions in `()` form are equivalent
     // to fresh bound regions, and that we can intermingle
     // named and anonymous as we choose:
-    eq::< for<'x,'y> Foo<(&'x isize,&'y usize),usize>,
+    eq::< for<'x,'y> Foo<(&'x isize,&'y usize),Output=usize>,
           for<'x,'y> Foo(&'x isize,&'y usize) -> usize            >();
-    eq::< for<'x,'y> Foo<(&'x isize,&'y usize),usize>,
+    eq::< for<'x,'y> Foo<(&'x isize,&'y usize),Output=usize>,
           for<'x> Foo(&'x isize,&usize) -> usize                  >();
-    eq::< for<'x,'y> Foo<(&'x isize,&'y usize),usize>,
+    eq::< for<'x,'y> Foo<(&'x isize,&'y usize),Output=usize>,
           for<'y> Foo(&isize,&'y usize) -> usize                  >();
-    eq::< for<'x,'y> Foo<(&'x isize,&'y usize),usize>,
+    eq::< for<'x,'y> Foo<(&'x isize,&'y usize),Output=usize>,
           Foo(&isize,&usize) -> usize                             >();
 
     // lifetime elision
-    eq::< for<'x> Foo<(&'x isize,), &'x isize>,
+    eq::< for<'x> Foo<(&'x isize,), Output=&'x isize>,
           Foo(&isize) -> &isize                                   >();
 
     // Errors expected:
-    eq::< Foo<(),()>,                   Foo(char)                     >();
-    //~^ ERROR not implemented
+    eq::< Foo<(),Output=()>,
+          Foo(char)                                               >();
+    //~^^ ERROR not implemented
 }
 
 fn main() { }
diff --git a/src/test/compile-fail/unboxed-closure-sugar-lifetime-elision.rs b/src/test/compile-fail/unboxed-closure-sugar-lifetime-elision.rs
index 29429c708d25..d2f781bba11e 100644
--- a/src/test/compile-fail/unboxed-closure-sugar-lifetime-elision.rs
+++ b/src/test/compile-fail/unboxed-closure-sugar-lifetime-elision.rs
@@ -16,8 +16,9 @@
 #![feature(unboxed_closures)]
 #![allow(dead_code)]
 
-trait Foo<T,U> {
-    fn dummy(&self, t: T, u: U);
+trait Foo<T> {
+    type Output;
+    fn dummy(&self, t: T);
 }
 
 trait Eq<X: ?Sized> { }
@@ -25,9 +26,9 @@ impl<X: ?Sized> Eq<X> for X { }
 fn eq<A: ?Sized,B: ?Sized +Eq<A>>() { }
 
 fn main() {
-    eq::< for<'a> Foo<(&'a isize,), &'a isize>,
+    eq::< for<'a> Foo<(&'a isize,), Output=&'a isize>,
           Foo(&isize) -> &isize                                   >();
-    eq::< for<'a> Foo<(&'a isize,), (&'a isize, &'a isize)>,
+    eq::< for<'a> Foo<(&'a isize,), Output=(&'a isize, &'a isize)>,
           Foo(&isize) -> (&isize, &isize)                           >();
 
     let _: Foo(&isize, &usize) -> &usize; //~ ERROR missing lifetime specifier
diff --git a/src/test/compile-fail/unboxed-closure-sugar-not-used-on-fn.rs b/src/test/compile-fail/unboxed-closure-sugar-not-used-on-fn.rs
index 21844e5b986c..1f0d5aae36db 100644
--- a/src/test/compile-fail/unboxed-closure-sugar-not-used-on-fn.rs
+++ b/src/test/compile-fail/unboxed-closure-sugar-not-used-on-fn.rs
@@ -11,11 +11,11 @@
 
 // Test that the `Fn` traits require `()` form without a feature gate.
 
-fn bar1(x: &Fn<(),()>) {
+fn bar1(x: &Fn<()>) {
     //~^ ERROR angle-bracket notation is not stable when used with the `Fn` family
 }
 
-fn bar2<T>(x: &T) where T: Fn<(),()> {
+fn bar2<T>(x: &T) where T: Fn<()> {
     //~^ ERROR angle-bracket notation is not stable when used with the `Fn` family
 }
 
diff --git a/src/test/compile-fail/unboxed-closure-sugar-region.rs b/src/test/compile-fail/unboxed-closure-sugar-region.rs
index c8dd33c11fd3..75688e44e807 100644
--- a/src/test/compile-fail/unboxed-closure-sugar-region.rs
+++ b/src/test/compile-fail/unboxed-closure-sugar-region.rs
@@ -17,8 +17,9 @@
 
 use std::marker;
 
-trait Foo<'a,T,U> {
-    fn dummy(&'a self) -> &'a (T,U);
+trait Foo<'a,T> {
+    type Output;
+    fn dummy(&'a self) -> &'a (T,Self::Output);
 }
 
 trait Eq<X: ?Sized> { }
@@ -29,16 +30,17 @@ fn same_type<A,B:Eq<A>>(a: A, b: B) { }
 
 fn test<'a,'b>() {
     // Parens are equivalent to omitting default in angle.
-    eq::< Foo<(isize,),()>,               Foo(isize)                      >();
+    eq::< Foo<(isize,),Output=()>,               Foo(isize)                      >();
 
     // Here we specify 'static explicitly in angle-bracket version.
     // Parenthesized winds up getting inferred.
-    eq::< Foo<'static, (isize,),()>,      Foo(isize)                      >();
+    eq::< Foo<'static, (isize,),Output=()>,      Foo(isize)                      >();
 }
 
-fn test2(x: &Foo<(isize,),()>, y: &Foo(isize)) {
+fn test2(x: &Foo<(isize,),Output=()>, y: &Foo(isize)) {
     // Here, the omitted lifetimes are expanded to distinct things.
     same_type(x, y) //~ ERROR cannot infer
+                    //~^ ERROR cannot infer
 }
 
 fn main() { }
diff --git a/src/test/compile-fail/unboxed-closure-sugar-used-on-struct-1.rs b/src/test/compile-fail/unboxed-closure-sugar-used-on-struct-1.rs
index a6184caf68b1..a3991a87b78f 100644
--- a/src/test/compile-fail/unboxed-closure-sugar-used-on-struct-1.rs
+++ b/src/test/compile-fail/unboxed-closure-sugar-used-on-struct-1.rs
@@ -11,13 +11,14 @@
 
 // Test that parentheses form doesn't work with struct types appearing in local variables.
 
-struct Bar<A,R> {
-    f: A, r: R
+struct Bar<A> {
+    f: A
 }
 
 fn bar() {
     let x: Box<Bar()> = panic!();
     //~^ ERROR parenthesized parameters may only be used with a trait
+    //~^^ ERROR associated type bindings are not allowed here
 }
 
 fn main() { }
diff --git a/src/test/compile-fail/unboxed-closure-sugar-used-on-struct.rs b/src/test/compile-fail/unboxed-closure-sugar-used-on-struct.rs
index d5fb505715e9..ad85cdcaa03a 100644
--- a/src/test/compile-fail/unboxed-closure-sugar-used-on-struct.rs
+++ b/src/test/compile-fail/unboxed-closure-sugar-used-on-struct.rs
@@ -10,12 +10,13 @@
 
 // Test that parentheses form doesn't work with struct types appearing in argument types.
 
-struct Bar<A,R> {
-    f: A, r: R
+struct Bar<A> {
+    f: A
 }
 
 fn foo(b: Box<Bar()>) {
     //~^ ERROR parenthesized parameters may only be used with a trait
+    //~^^ ERROR associated type bindings are not allowed here
 }
 
 fn main() { }
diff --git a/src/test/compile-fail/unboxed-closure-sugar-wrong-number-number-type-parameters-1.rs b/src/test/compile-fail/unboxed-closure-sugar-wrong-number-number-type-parameters-1.rs
index d9efab974d83..c9837da58e75 100644
--- a/src/test/compile-fail/unboxed-closure-sugar-wrong-number-number-type-parameters-1.rs
+++ b/src/test/compile-fail/unboxed-closure-sugar-wrong-number-number-type-parameters-1.rs
@@ -12,7 +12,7 @@
 
 trait One<A> { fn foo(&self) -> A; }
 
-fn foo(_: &One()) //~ ERROR wrong number of type arguments
+fn foo(_: &One()) //~ ERROR no associated type `Output` defined in `One<()>`
 {}
 
 fn main() { }
diff --git a/src/test/compile-fail/unboxed-closure-sugar-wrong-trait.rs b/src/test/compile-fail/unboxed-closure-sugar-wrong-trait.rs
index b58e08355c11..e63f510b890d 100644
--- a/src/test/compile-fail/unboxed-closure-sugar-wrong-trait.rs
+++ b/src/test/compile-fail/unboxed-closure-sugar-wrong-trait.rs
@@ -13,7 +13,7 @@
 trait Trait {}
 
 fn f<F:Trait(isize) -> isize>(x: F) {}
-//~^ ERROR wrong number of type arguments: expected 0, found 2
+//~^ ERROR wrong number of type arguments: expected 0, found 1
 
 fn main() {}
 
diff --git a/src/test/compile-fail/unboxed-closures-fnmut-as-fn.rs b/src/test/compile-fail/unboxed-closures-fnmut-as-fn.rs
index fc87ec9f9598..bbafd5109edf 100644
--- a/src/test/compile-fail/unboxed-closures-fnmut-as-fn.rs
+++ b/src/test/compile-fail/unboxed-closures-fnmut-as-fn.rs
@@ -18,7 +18,9 @@ use std::ops::{Fn,FnMut,FnOnce};
 
 struct S;
 
-impl FnMut<(isize,),isize> for S {
+impl FnMut<(isize,)> for S {
+    type Output = isize;
+
     extern "rust-call" fn call_mut(&mut self, (x,): (isize,)) -> isize {
         x * x
     }
@@ -29,6 +31,8 @@ fn call_it<F:Fn(isize)->isize>(f: &F, x: isize) -> isize {
 }
 
 fn main() {
-    let x = call_it(&S, 22); //~ ERROR not implemented
+    let x = call_it(&S, 22);
+    //~^ ERROR not implemented
+    //~| ERROR not implemented
 }
 
diff --git a/src/test/compile-fail/unboxed-closures-unsafe-extern-fn.rs b/src/test/compile-fail/unboxed-closures-unsafe-extern-fn.rs
index ab909717cab6..23f7ee2b0101 100644
--- a/src/test/compile-fail/unboxed-closures-unsafe-extern-fn.rs
+++ b/src/test/compile-fail/unboxed-closures-unsafe-extern-fn.rs
@@ -21,7 +21,9 @@ fn call_it_mut<F:FnMut(&isize)->isize>(_: &mut F, _: isize) -> isize { 0 }
 fn call_it_once<F:FnOnce(&isize)->isize>(_: F, _: isize) -> isize { 0 }
 
 fn a() {
-    let x = call_it(&square, 22); //~ ERROR not implemented
+    let x = call_it(&square, 22);
+    //~^ ERROR not implemented
+    //~| ERROR not implemented
 }
 
 fn b() {
diff --git a/src/test/compile-fail/unboxed-closures-vtable-mismatch.rs b/src/test/compile-fail/unboxed-closures-vtable-mismatch.rs
index 95673a513190..305dd33e5a05 100644
--- a/src/test/compile-fail/unboxed-closures-vtable-mismatch.rs
+++ b/src/test/compile-fail/unboxed-closures-vtable-mismatch.rs
@@ -12,13 +12,15 @@
 
 use std::ops::FnMut;
 
-fn call_it<F:FnMut<(isize,isize),isize>>(y: isize, mut f: F) -> isize {
+fn call_it<F:FnMut(isize,isize)->isize>(y: isize, mut f: F) -> isize {
     f(2, y)
 }
 
 pub fn main() {
     let f = |&mut: x: usize, y: isize| -> isize { (x as isize) + y };
-    let z = call_it(3, f);  //~ ERROR type mismatch
+    let z = call_it(3, f);
+    //~^ ERROR type mismatch
+    //~| ERROR type mismatch
     println!("{}", z);
 }
 
diff --git a/src/test/compile-fail/unboxed-closures-wrong-abi.rs b/src/test/compile-fail/unboxed-closures-wrong-abi.rs
index 4a0b55558c04..96619bef36fd 100644
--- a/src/test/compile-fail/unboxed-closures-wrong-abi.rs
+++ b/src/test/compile-fail/unboxed-closures-wrong-abi.rs
@@ -21,7 +21,9 @@ fn call_it_mut<F:FnMut(&isize)->isize>(_: &mut F, _: isize) -> isize { 0 }
 fn call_it_once<F:FnOnce(&isize)->isize>(_: F, _: isize) -> isize { 0 }
 
 fn a() {
-    let x = call_it(&square, 22); //~ ERROR not implemented
+    let x = call_it(&square, 22);
+    //~^ ERROR not implemented
+    //~| ERROR not implemented
 }
 
 fn b() {
diff --git a/src/test/compile-fail/unboxed-closures-wrong-arg-type-extern-fn.rs b/src/test/compile-fail/unboxed-closures-wrong-arg-type-extern-fn.rs
index b2fdf7926301..ebcbdbbc006d 100644
--- a/src/test/compile-fail/unboxed-closures-wrong-arg-type-extern-fn.rs
+++ b/src/test/compile-fail/unboxed-closures-wrong-arg-type-extern-fn.rs
@@ -22,7 +22,9 @@ fn call_it_mut<F:FnMut(&isize)->isize>(_: &mut F, _: isize) -> isize { 0 }
 fn call_it_once<F:FnOnce(&isize)->isize>(_: F, _: isize) -> isize { 0 }
 
 fn a() {
-    let x = call_it(&square, 22); //~ ERROR not implemented
+    let x = call_it(&square, 22);
+    //~^ ERROR not implemented
+    //~| ERROR not implemented
 }
 
 fn b() {
diff --git a/src/test/compile-fail/unboxed-closures-wrong-trait.rs b/src/test/compile-fail/unboxed-closures-wrong-trait.rs
index e4255d0024fe..2ada0dd22e75 100644
--- a/src/test/compile-fail/unboxed-closures-wrong-trait.rs
+++ b/src/test/compile-fail/unboxed-closures-wrong-trait.rs
@@ -18,5 +18,6 @@ fn main() {
     let z: isize = 7;
     assert_eq!(c(|&mut: x: isize, y| x + y + z), 10);
     //~^ ERROR not implemented
+    //~| ERROR not implemented
 }
 
diff --git a/src/test/run-pass/bare-fn-implements-fn-mut.rs b/src/test/run-pass/bare-fn-implements-fn-mut.rs
index 9d104afd6464..fae83d4aa656 100644
--- a/src/test/run-pass/bare-fn-implements-fn-mut.rs
+++ b/src/test/run-pass/bare-fn-implements-fn-mut.rs
@@ -12,7 +12,7 @@
 
 use std::ops::FnMut;
 
-fn call_f<F:FnMut<(),()>>(mut f: F) {
+fn call_f<F:FnMut()>(mut f: F) {
     f();
 }
 
@@ -20,7 +20,7 @@ fn f() {
     println!("hello");
 }
 
-fn call_g<G:FnMut<(String,String),String>>(mut g: G, x: String, y: String)
+fn call_g<G:FnMut(String,String) -> String>(mut g: G, x: String, y: String)
           -> String {
     g(x, y)
 }
diff --git a/src/test/run-pass/hrtb-parse.rs b/src/test/run-pass/hrtb-parse.rs
index 41b7c0fae074..d5307c09103a 100644
--- a/src/test/run-pass/hrtb-parse.rs
+++ b/src/test/run-pass/hrtb-parse.rs
@@ -22,23 +22,23 @@ trait Get<A,R> {
 // Parse HRTB with explicit `for` in a where-clause:
 
 fn foo00<T>(t: T)
-    where T : for<'a> Get<&'a int, &'a int>
+    where T : for<'a> Get<&'a i32, &'a i32>
 {
 }
 
-fn foo01<T: for<'a> Get<&'a int, &'a int>>(t: T)
+fn foo01<T: for<'a> Get<&'a i32, &'a i32>>(t: T)
 {
 }
 
 // Parse HRTB with explicit `for` in various sorts of types:
 
-fn foo10(t: Box<for<'a> Get<int, int>>) { }
-fn foo11(t: Box<for<'a> Get(int) -> int>) { }
+fn foo10(t: Box<for<'a> Get<i32, i32>>) { }
+fn foo11(t: Box<for<'a> Fn(i32) -> i32>) { }
 
-fn foo20(t: for<'a> fn(int) -> int) { }
-fn foo21(t: for<'a> unsafe fn(int) -> int) { }
-fn foo22(t: for<'a> extern "C" fn(int) -> int) { }
-fn foo23(t: for<'a> unsafe extern "C" fn(int) -> int) { }
+fn foo20(t: for<'a> fn(i32) -> i32) { }
+fn foo21(t: for<'a> unsafe fn(i32) -> i32) { }
+fn foo22(t: for<'a> extern "C" fn(i32) -> i32) { }
+fn foo23(t: for<'a> unsafe extern "C" fn(i32) -> i32) { }
 
 fn main() {
 }
diff --git a/src/test/run-pass/hrtb-trait-object-paren-notation.rs b/src/test/run-pass/hrtb-trait-object-paren-notation.rs
index e17e0ae2189d..1b62a8e809c8 100644
--- a/src/test/run-pass/hrtb-trait-object-paren-notation.rs
+++ b/src/test/run-pass/hrtb-trait-object-paren-notation.rs
@@ -16,7 +16,7 @@ trait FnLike<A,R> {
     fn call(&self, arg: A) -> R;
 }
 
-type FnObject<'b> = for<'a> FnLike(&'a int) -> (&'a int) + 'b;
+type FnObject<'b> = for<'a> FnLike<(&'a i32,), &'a i32> + 'b;
 
 struct Identity;
 
diff --git a/src/test/run-pass/issue-13655.rs b/src/test/run-pass/issue-13655.rs
index 6fdaac992047..81a8b29461c7 100644
--- a/src/test/run-pass/issue-13655.rs
+++ b/src/test/run-pass/issue-13655.rs
@@ -13,7 +13,8 @@ use std::ops::Fn;
 
 struct Foo<T>(T);
 
-impl<T: Copy> Fn<(), T> for Foo<T> {
+impl<T: Copy> Fn<()> for Foo<T> {
+    type Output = T;
     extern "rust-call" fn call(&self, _: ()) -> T {
       match *self {
         Foo(t) => t
diff --git a/src/test/run-pass/issue-14958.rs b/src/test/run-pass/issue-14958.rs
index 1ffd349a6538..814a743648d3 100644
--- a/src/test/run-pass/issue-14958.rs
+++ b/src/test/run-pass/issue-14958.rs
@@ -14,7 +14,8 @@ trait Foo {}
 
 struct Bar;
 
-impl<'a> std::ops::Fn<(&'a (Foo+'a),), ()> for Bar {
+impl<'a> std::ops::Fn<(&'a (Foo+'a),)> for Bar {
+    type Output = ();
     extern "rust-call" fn call(&self, _: (&'a Foo,)) {}
 }
 
diff --git a/src/test/run-pass/issue-14959.rs b/src/test/run-pass/issue-14959.rs
index 99472bb3610f..33281d7d78ff 100644
--- a/src/test/run-pass/issue-14959.rs
+++ b/src/test/run-pass/issue-14959.rs
@@ -33,7 +33,9 @@ impl Alloy {
     }
 }
 
-impl<'a, 'b> Fn<(&'b mut (Response+'b),),()> for SendFile<'a> {
+impl<'a, 'b> Fn<(&'b mut (Response+'b),)> for SendFile<'a> {
+    type Output = ();
+
     extern "rust-call" fn call(&self, (_res,): (&'b mut (Response+'b),)) {}
 }
 
diff --git a/src/test/run-pass/issue-16668.rs b/src/test/run-pass/issue-16668.rs
index 75b1e11ddc1e..e82add61aa3b 100644
--- a/src/test/run-pass/issue-16668.rs
+++ b/src/test/run-pass/issue-16668.rs
@@ -15,7 +15,7 @@
 #![feature(unboxed_closures)]
 
 struct Parser<'a, I, O> {
-    parse: Box<FnMut<(I,), Result<O, String>> + 'a>
+    parse: Box<FnMut(I) -> Result<O, String> + 'a>
 }
 
 impl<'a, I, O: 'a> Parser<'a, I, O> {
diff --git a/src/test/run-pass/issue-16739.rs b/src/test/run-pass/issue-16739.rs
index cb6f068cf45b..389baecafd14 100644
--- a/src/test/run-pass/issue-16739.rs
+++ b/src/test/run-pass/issue-16739.rs
@@ -15,27 +15,30 @@
 // Test that unboxing shim for calling rust-call ABI methods through a
 // trait box works and does not cause an ICE.
 
-struct Foo { foo: uint }
+struct Foo { foo: u32 }
 
-impl FnMut<(), uint> for Foo {
-    extern "rust-call" fn call_mut(&mut self, _: ()) -> uint { self.foo }
+impl FnMut<()> for Foo {
+    type Output = u32;
+    extern "rust-call" fn call_mut(&mut self, _: ()) -> u32 { self.foo }
 }
 
-impl FnMut<(uint,), uint> for Foo {
-    extern "rust-call" fn call_mut(&mut self, (x,): (uint,)) -> uint { self.foo + x }
+impl FnMut<(u32,)> for Foo {
+    type Output = u32;
+    extern "rust-call" fn call_mut(&mut self, (x,): (u32,)) -> u32 { self.foo + x }
 }
 
-impl FnMut<(uint, uint), uint> for Foo {
-    extern "rust-call" fn call_mut(&mut self, (x, y): (uint, uint)) -> uint { self.foo + x + y }
+impl FnMut<(u32,u32)> for Foo {
+    type Output = u32;
+    extern "rust-call" fn call_mut(&mut self, (x, y): (u32, u32)) -> u32 { self.foo + x + y }
 }
 
 fn main() {
-    let mut f = box Foo { foo: 42 } as Box<FnMut<(), uint>>;
+    let mut f = box Foo { foo: 42 } as Box<FnMut() -> u32>;
     assert_eq!(f.call_mut(()), 42);
 
-    let mut f = box Foo { foo: 40 } as Box<FnMut<(uint,), uint>>;
+    let mut f = box Foo { foo: 40 } as Box<FnMut(u32) -> u32>;
     assert_eq!(f.call_mut((2,)), 42);
 
-    let mut f = box Foo { foo: 40 } as Box<FnMut<(uint, uint), uint>>;
+    let mut f = box Foo { foo: 40 } as Box<FnMut(u32, u32) -> u32>;
     assert_eq!(f.call_mut((1, 1)), 42);
 }
diff --git a/src/test/run-pass/overloaded-calls-param-vtables.rs b/src/test/run-pass/overloaded-calls-param-vtables.rs
index 56887636d5df..2838909c1be6 100644
--- a/src/test/run-pass/overloaded-calls-param-vtables.rs
+++ b/src/test/run-pass/overloaded-calls-param-vtables.rs
@@ -17,13 +17,15 @@ use std::ops::Add;
 
 struct G<A>;
 
-impl<'a, A: Add<int, Output=int>> Fn<(A,), int> for G<A> {
-    extern "rust-call" fn call(&self, (arg,): (A,)) -> int {
+impl<'a, A: Add<i32, Output=i32>> Fn<(A,)> for G<A> {
+    type Output = i32;
+
+    extern "rust-call" fn call(&self, (arg,): (A,)) -> i32 {
         arg.add(1)
     }
 }
 
 fn main() {
     // ICE trigger
-    G(1i);
+    G(1_i32);
 }
diff --git a/src/test/run-pass/overloaded-calls-simple.rs b/src/test/run-pass/overloaded-calls-simple.rs
index bb5b88d3674a..f9e838d9b3d3 100644
--- a/src/test/run-pass/overloaded-calls-simple.rs
+++ b/src/test/run-pass/overloaded-calls-simple.rs
@@ -13,34 +13,37 @@
 use std::ops::{Fn, FnMut, FnOnce};
 
 struct S1 {
-    x: int,
-    y: int,
+    x: i32,
+    y: i32,
 }
 
-impl FnMut<(int,),int> for S1 {
-    extern "rust-call" fn call_mut(&mut self, (z,): (int,)) -> int {
+impl FnMut<(i32,)> for S1 {
+    type Output = i32;
+    extern "rust-call" fn call_mut(&mut self, (z,): (i32,)) -> i32 {
         self.x * self.y * z
     }
 }
 
 struct S2 {
-    x: int,
-    y: int,
+    x: i32,
+    y: i32,
 }
 
-impl Fn<(int,),int> for S2 {
-    extern "rust-call" fn call(&self, (z,): (int,)) -> int {
+impl Fn<(i32,)> for S2 {
+    type Output = i32;
+    extern "rust-call" fn call(&self, (z,): (i32,)) -> i32 {
         self.x * self.y * z
     }
 }
 
 struct S3 {
-    x: int,
-    y: int,
+    x: i32,
+    y: i32,
 }
 
-impl FnOnce<(int,int),int> for S3 {
-    extern "rust-call" fn call_once(self, (z,zz): (int,int)) -> int {
+impl FnOnce<(i32,i32)> for S3 {
+    type Output = i32;
+    extern "rust-call" fn call_once(self, (z,zz): (i32,i32)) -> i32 {
         self.x * self.y * z * zz
     }
 }
diff --git a/src/test/run-pass/overloaded-calls-zero-args.rs b/src/test/run-pass/overloaded-calls-zero-args.rs
index 809a251fe805..ce7395673b39 100644
--- a/src/test/run-pass/overloaded-calls-zero-args.rs
+++ b/src/test/run-pass/overloaded-calls-zero-args.rs
@@ -13,12 +13,13 @@
 use std::ops::{FnMut};
 
 struct S {
-    x: int,
-    y: int,
+    x: i32,
+    y: i32,
 }
 
-impl FnMut<(),int> for S {
-    extern "rust-call" fn call_mut(&mut self, (): ()) -> int {
+impl FnMut<()> for S {
+    type Output = i32;
+    extern "rust-call" fn call_mut(&mut self, (): ()) -> i32 {
         self.x * self.y
     }
 }
diff --git a/src/test/run-pass/unboxed-closures-boxed.rs b/src/test/run-pass/unboxed-closures-boxed.rs
index dc35d5bf2cac..27528ca5d566 100644
--- a/src/test/run-pass/unboxed-closures-boxed.rs
+++ b/src/test/run-pass/unboxed-closures-boxed.rs
@@ -14,9 +14,9 @@
 
 use std::ops::FnMut;
 
- fn make_adder(x: int) -> Box<FnMut<(int,),int>+'static> {
-    (box move |&mut: y: int| -> int { x + y }) as
-        Box<FnMut<(int,),int>+'static>
+ fn make_adder(x: i32) -> Box<FnMut(i32)->i32+'static> {
+    (box move |&mut: y: i32| -> i32 { x + y }) as
+        Box<FnMut(i32)->i32+'static>
 }
 
 pub fn main() {
diff --git a/src/test/run-pass/unboxed-closures-fn-as-fnmut-and-fnonce.rs b/src/test/run-pass/unboxed-closures-fn-as-fnmut-and-fnonce.rs
index 8af0547e5e57..5d6029e703b8 100644
--- a/src/test/run-pass/unboxed-closures-fn-as-fnmut-and-fnonce.rs
+++ b/src/test/run-pass/unboxed-closures-fn-as-fnmut-and-fnonce.rs
@@ -18,21 +18,22 @@ use std::ops::{Fn,FnMut,FnOnce};
 
 struct S;
 
-impl Fn<(int,),int> for S {
-    extern "rust-call" fn call(&self, (x,): (int,)) -> int {
+impl Fn<(i32,)> for S {
+    type Output = i32;
+    extern "rust-call" fn call(&self, (x,): (i32,)) -> i32 {
         x * x
     }
 }
 
-fn call_it<F:Fn(int)->int>(f: &F, x: int) -> int {
+fn call_it<F:Fn(i32)->i32>(f: &F, x: i32) -> i32 {
     f(x)
 }
 
-fn call_it_mut<F:FnMut(int)->int>(f: &mut F, x: int) -> int {
+fn call_it_mut<F:FnMut(i32)->i32>(f: &mut F, x: i32) -> i32 {
     f(x)
 }
 
-fn call_it_once<F:FnOnce(int)->int>(f: F, x: int) -> int {
+fn call_it_once<F:FnOnce(i32)->i32>(f: F, x: i32) -> i32 {
     f(x)
 }
 
diff --git a/src/test/run-pass/unboxed-closures-fnmut-as-fnonce.rs b/src/test/run-pass/unboxed-closures-fnmut-as-fnonce.rs
index 068080e256db..95dae41c6840 100644
--- a/src/test/run-pass/unboxed-closures-fnmut-as-fnonce.rs
+++ b/src/test/run-pass/unboxed-closures-fnmut-as-fnonce.rs
@@ -18,17 +18,19 @@ use std::ops::{FnMut,FnOnce};
 
 struct S;
 
-impl FnMut<(int,),int> for S {
-    extern "rust-call" fn call_mut(&mut self, (x,): (int,)) -> int {
+impl FnMut<(i32,)> for S {
+    type Output = i32;
+
+    extern "rust-call" fn call_mut(&mut self, (x,): (i32,)) -> i32 {
         x * x
     }
 }
 
-fn call_it_mut<F:FnMut(int)->int>(f: &mut F, x: int) -> int {
+fn call_it_mut<F:FnMut(i32)->i32>(f: &mut F, x: i32) -> i32 {
     f(x)
 }
 
-fn call_it_once<F:FnOnce(int)->int>(f: F, x: int) -> int {
+fn call_it_once<F:FnOnce(i32)->i32>(f: F, x: i32) -> i32 {
     f(x)
 }
 
diff --git a/src/test/run-pass/unboxed-closures-generic.rs b/src/test/run-pass/unboxed-closures-generic.rs
index 0edeeb8d198d..04c124946c9a 100644
--- a/src/test/run-pass/unboxed-closures-generic.rs
+++ b/src/test/run-pass/unboxed-closures-generic.rs
@@ -12,12 +12,12 @@
 
 use std::ops::FnMut;
 
-fn call_it<F:FnMut<(int,int),int>>(y: int, mut f: F) -> int {
+fn call_it<F:FnMut(i32,i32)->i32>(y: i32, mut f: F) -> i32 {
     f(2, y)
 }
 
 pub fn main() {
-    let f = |&mut: x: int, y: int| -> int { x + y };
+    let f = |&mut: x: i32, y: i32| -> i32 { x + y };
     let z = call_it(3, f);
     println!("{}", z);
     assert_eq!(z, 5);
diff --git a/src/test/run-pass/unboxed-closures-manual-impl.rs b/src/test/run-pass/unboxed-closures-manual-impl.rs
index 88c9ceae4a12..37075de0405a 100644
--- a/src/test/run-pass/unboxed-closures-manual-impl.rs
+++ b/src/test/run-pass/unboxed-closures-manual-impl.rs
@@ -15,17 +15,19 @@ use std::ops::FnMut;
 
 struct S;
 
-impl FnMut<(int,),int> for S {
-    extern "rust-call" fn call_mut(&mut self, (x,): (int,)) -> int {
+impl FnMut<(i32,)> for S {
+    type Output = i32;
+
+    extern "rust-call" fn call_mut(&mut self, (x,): (i32,)) -> i32 {
         x * x
     }
 }
 
-fn call_it<F:FnMut(int)->int>(mut f: F, x: int) -> int {
+fn call_it<F:FnMut(i32)->i32>(mut f: F, x: i32) -> i32 {
     f(x) + 3
 }
 
-fn call_box(f: &mut FnMut(int) -> int, x: int) -> int {
+fn call_box(f: &mut FnMut(i32) -> i32, x: i32) -> i32 {
     f(x) + 3
 }
 
diff --git a/src/test/run-pass/unboxed-closures-monomorphization.rs b/src/test/run-pass/unboxed-closures-monomorphization.rs
index 6701f879e4f2..6dfa4c124e24 100644
--- a/src/test/run-pass/unboxed-closures-monomorphization.rs
+++ b/src/test/run-pass/unboxed-closures-monomorphization.rs
@@ -16,17 +16,17 @@
 #![feature(unboxed_closures)]
 
 fn main(){
-    fn bar<'a, T:Clone+'a> (t: T) -> Box<FnMut<(),T> + 'a> {
+    fn bar<'a, T:Clone+'a> (t: T) -> Box<FnMut()->T + 'a> {
         box move |&mut:| t.clone()
     }
 
-    let mut f = bar(42u);
+    let mut f = bar(42_u32);
     assert_eq!(f.call_mut(()), 42);
 
     let mut f = bar("forty-two");
     assert_eq!(f.call_mut(()), "forty-two");
 
-    let x = 42u;
+    let x = 42_u32;
     let mut f = bar(&x);
     assert_eq!(f.call_mut(()), &x);
 
diff --git a/src/test/run-pass/unboxed-closures-sugar-object.rs b/src/test/run-pass/unboxed-closures-sugar-object.rs
index d65de438514f..fff841a2f052 100644
--- a/src/test/run-pass/unboxed-closures-sugar-object.rs
+++ b/src/test/run-pass/unboxed-closures-sugar-object.rs
@@ -29,7 +29,7 @@ impl<X> Getter<X,X> for Identity {
 }
 
 fn main() {
-    let x: &Getter(int) -> (int,) = &Identity;
+    let x: &Getter<(i32,), (i32,)> = &Identity;
     let (y,) = x.get((22,));
     assert_eq!(y, 22);
 }