Address nits by @pnkfelix

Author: nikomatsakis

src/librustc/middle/infer/error_reporting.rs

@@ -619,7 +619,7 @@ impl<'a, 'tcx> ErrorReporting<'tcx> for InferCtxt<'a, 'tcx> {
             infer::RelateRegionParamBound(span) => {
                 self.tcx.sess.span_err(
                     span,
-                    "declared lifetime bound not satisfied");
+                    "lifetime bound not satisfied");
                 note_and_explain_region(
                     self.tcx,
                     "lifetime parameter instantiated with ",
@@ -1629,7 +1629,7 @@ impl<'a, 'tcx> ErrorReportingHelpers<'tcx> for InferCtxt<'a, 'tcx> {
                 self.tcx.sess.span_note(
                     span,
                     &format!("...so that the type `{}` \
-                             will meet the declared lifetime bounds",
+                             will meet its required lifetime bounds",
                             self.ty_to_string(t))[]);
             }
             infer::RelateDefaultParamBound(span, t) => {

src/librustc_typeck/astconv.rs

@@ -1754,6 +1754,12 @@ fn compute_object_lifetime_bound<'tcx>(
     return r;
 }
 
+/// Given an object type like `SomeTrait+Send`, computes the lifetime
+/// bounds that must hold on the elided self type. These are derived
+/// from the declarations of `SomeTrait`, `Send`, and friends -- if
+/// they declare `trait SomeTrait : 'static`, for example, then
+/// `'static` would appear in the list. The hard work is done by
+/// `ty::required_region_bounds`, see that for more information.
 pub fn object_region_bounds<'tcx>(
     tcx: &ty::ctxt<'tcx>,
     principal: &ty::PolyTraitRef<'tcx>,

src/librustc_typeck/check/regionck.rs

@@ -154,7 +154,7 @@ pub fn regionck_ensure_component_tys_wf<'a, 'tcx>(fcx: &FnCtxt<'a, 'tcx>,
         // empty region is a subregion of all others, this can't fail
         // unless the type does not meet the well-formedness
         // requirements.
-        type_must_outlive(&mut rcx, infer::RelateRegionParamBound(span),
+        type_must_outlive(&mut rcx, infer::RelateParamBound(span, component_ty),
                           component_ty, ty::ReEmpty);
     }
 }
@@ -305,7 +305,7 @@ impl<'a, 'tcx> Rcx<'a, 'tcx> {
             debug!("visit_region_obligations: r_o={}",
                    r_o.repr(self.tcx()));
             let sup_type = self.resolve_type(r_o.sup_type);
-            let origin = infer::RelateRegionParamBound(r_o.cause.span);
+            let origin = infer::RelateParamBound(r_o.cause.span, sup_type);
             type_must_outlive(self, origin, sup_type, r_o.sub_region);
         }
 

src/test/compile-fail/builtin-superkinds-simple.rs

@@ -14,6 +14,6 @@
 trait Foo : Send { }
 
 impl <'a> Foo for &'a mut () { }
-//~^ ERROR declared lifetime bound not satisfied
+//~^ ERROR the type `&'a mut ()` does not fulfill the required lifetime
 
 fn main() { }

src/test/compile-fail/kindck-impl-type-params.rs

@@ -36,7 +36,7 @@ fn g<T>(val: T) {
 fn foo<'a>() {
     let t: S<&'a isize> = S;
     let a = &t as &Gettable<&'a isize>;
-    //~^ ERROR declared lifetime bound not satisfied
+    //~^ ERROR the type `&'a isize` does not fulfill the required lifetime
 }
 
 fn foo2<'a>() {

src/test/compile-fail/kindck-send-object1.rs

@@ -22,7 +22,7 @@ fn test51<'a>() {
 }
 fn test52<'a>() {
     assert_send::<&'a (Dummy+Send)>();
-    //~^ ERROR declared lifetime bound not satisfied
+    //~^ ERROR does not fulfill the required lifetime
 }
 
 // ...unless they are properly bounded

src/test/compile-fail/kindck-send-owned.rs

@@ -19,7 +19,7 @@ fn test32() { assert_send::<Vec<isize> >(); }
 
 // but not if they own a bad thing
 fn test40<'a>(_: &'a isize) {
-    assert_send::<Box<&'a isize>>(); //~ ERROR declared lifetime bound not satisfied
+    assert_send::<Box<&'a isize>>(); //~ ERROR does not fulfill the required lifetime
 }
 
 fn main() { }

src/test/compile-fail/kindck-send-region-pointers.rs

@@ -22,13 +22,13 @@ fn test10() { assert_send::<&'static mut isize>(); }
 
 // otherwise lifetime pointers are not ok
 fn test20<'a>(_: &'a isize) {
-    assert_send::<&'a isize>(); //~ ERROR declared lifetime bound not satisfied
+    assert_send::<&'a isize>(); //~ ERROR does not fulfill the required lifetime
 }
 fn test21<'a>(_: &'a isize) {
-    assert_send::<&'a str>(); //~ ERROR declared lifetime bound not satisfied
+    assert_send::<&'a str>(); //~ ERROR does not fulfill the required lifetime
 }
 fn test22<'a>(_: &'a isize) {
-    assert_send::<&'a [isize]>(); //~ ERROR declared lifetime bound not satisfied
+    assert_send::<&'a [isize]>(); //~ ERROR does not fulfill the required lifetime
 }
 
 fn main() { }

src/test/compile-fail/object-lifetime-default-ambiguous.rs

@@ -49,7 +49,8 @@ fn d(t: Ref2<Ref1<Test>>) {
 fn e(t: Ref2<Ref0<Test>>) {
     //~^ ERROR lifetime bound for this object type cannot be deduced from context
     //
-    // In this case, Ref0 just inherits.
+    // In this case, Ref2 is ambiguous, and Ref0 inherits the
+    // ambiguity.
 }
 
 fn f(t: &Ref2<Test>) {

src/test/compile-fail/region-object-lifetime-in-coercion.rs

@@ -17,22 +17,22 @@ trait Foo {}
 impl<'a> Foo for &'a [u8] {}
 
 fn a(v: &[u8]) -> Box<Foo + 'static> {
-    let x: Box<Foo + 'static> = box v; //~ ERROR declared lifetime bound not satisfied
+    let x: Box<Foo + 'static> = box v; //~ ERROR does not fulfill the required lifetime
     x
 }
 
 fn b(v: &[u8]) -> Box<Foo + 'static> {
-    box v //~ ERROR declared lifetime bound not satisfied
+    box v //~ ERROR does not fulfill the required lifetime
 }
 
 fn c(v: &[u8]) -> Box<Foo> {
     // same as previous case due to RFC 599
 
-    box v //~ ERROR declared lifetime bound not satisfied
+    box v //~ ERROR does not fulfill the required lifetime
 }
 
 fn d<'a,'b>(v: &'a [u8]) -> Box<Foo+'b> {
-    box v //~ ERROR declared lifetime bound not satisfied
+    box v //~ ERROR does not fulfill the required lifetime
 }
 
 fn e<'a:'b,'b>(v: &'a [u8]) -> Box<Foo+'b> {