improve error message

Author: arielb1

src/doc/book/closures.md

@@ -371,13 +371,13 @@ assert_eq!(6, answer);
 This gives us these long, related errors:
 
 ```text
-error: the predicate `core::ops::Fn(i32) -> i32 : core::marker::Sized` is not satisfied [E0277]
+error: the trait bound `core::ops::Fn(i32) -> i32 : core::marker::Sized` is not satisfied [E0277]
 fn factory() -> (Fn(i32) -> i32) {
                 ^~~~~~~~~~~~~~~~
 note: `core::ops::Fn(i32) -> i32` does not have a constant size known at compile-time
 fn factory() -> (Fn(i32) -> i32) {
                 ^~~~~~~~~~~~~~~~
-error: the predicate `core::ops::Fn(i32) -> i32 : core::marker::Sized` is not satisfied [E0277]
+error: the trait bound `core::ops::Fn(i32) -> i32 : core::marker::Sized` is not satisfied [E0277]
 let f = factory();
     ^
 note: `core::ops::Fn(i32) -> i32` does not have a constant size known at compile-time

src/doc/book/concurrency.md

@@ -231,7 +231,7 @@ fn main() {
 This won't work, however, and will give us the error:
 
 ```text
-13:9: 13:22 error: the predicate `alloc::rc::Rc<collections::vec::Vec<i32>> : core::marker::Send`
+13:9: 13:22 error: the trait bound `alloc::rc::Rc<collections::vec::Vec<i32>> : core::marker::Send`
             is not satisfied
 ...
 13:9: 13:22 note: `alloc::rc::Rc<collections::vec::Vec<i32>>`

src/doc/book/traits.md

@@ -154,7 +154,7 @@ print_area(5);
 We get a compile-time error:
 
 ```text
-error: the predicate `_ : HasArea` is not satisfied [E0277]
+error: the trait bound `_ : HasArea` is not satisfied [E0277]
 ```
 
 ## Trait bounds on generic structs
@@ -496,7 +496,7 @@ impl FooBar for Baz {
 If we forget to implement `Foo`, Rust will tell us:
 
 ```text
-error: the predicate `main::Baz : main::Foo` is not satisfied [E0277]
+error: the trait bound `main::Baz : main::Foo` is not satisfied [E0277]
 ```
 
 # Deriving

src/doc/book/vectors.md

@@ -56,7 +56,7 @@ v[j];
 Indexing with a non-`usize` type gives an error that looks like this:
 
 ```text
-error: the predicate `collections::vec::Vec<_> : core::ops::Index<i32>`
+error: the trait bound `collections::vec::Vec<_> : core::ops::Index<i32>`
 is not satisfied [E0277]
 v[j];
 ^~~~

src/doc/nomicon/coercions.md

@@ -64,7 +64,7 @@ fn main() {
 ```
 
 ```text
-<anon>:10:5: 10:8 error: the predicate `&mut i32 : Trait` is not satisfied [E0277]
+<anon>:10:5: 10:8 error: the trait bound `&mut i32 : Trait` is not satisfied [E0277]
 <anon>:10     foo(t);
               ^~~
 ```

src/librustc/diagnostics.rs

@@ -1006,7 +1006,7 @@ fn some_func<T: Foo>(foo: T) {
 fn main() {
     // we now call the method with the i32 type, which doesn't implement
     // the Foo trait
-    some_func(5i32); // error: the predicate `i32 : Foo` is not satisfied
+    some_func(5i32); // error: the trait bound `i32 : Foo` is not satisfied
 }
 ```
 

src/librustc/traits/error_reporting.rs

@@ -361,7 +361,7 @@ pub fn report_selection_error<'a, 'tcx>(infcx: &InferCtxt<'a, 'tcx>,
                             let trait_ref = trait_predicate.to_poly_trait_ref();
                             let mut err = struct_span_err!(
                                 infcx.tcx.sess, obligation.cause.span, E0277,
-                                "the predicate `{}` is not satisfied",
+                                "the trait bound `{}` is not satisfied",
                                 trait_ref.to_predicate());
 
                             // Try to report a good error message.

src/test/compile-fail/associated-types-for-unimpl-trait.rs

@@ -15,7 +15,7 @@ trait Get {
 
 trait Other {
     fn uhoh<U:Get>(&self, foo: U, bar: <Self as Get>::Value) {}
-    //~^ ERROR the predicate `Self : Get` is not satisfied
+    //~^ ERROR the trait bound `Self : Get` is not satisfied
 }
 
 fn main() {

src/test/compile-fail/associated-types-invalid-trait-ref-issue-18865.rs

@@ -18,7 +18,7 @@ trait Foo<T> {
 
 fn f<T:Foo<isize>>(t: &T) {
     let u: <T as Foo<usize>>::Bar = t.get_bar();
-    //~^ ERROR the predicate `T : Foo<usize>` is not satisfied
+    //~^ ERROR the trait bound `T : Foo<usize>` is not satisfied
 }
 
 fn main() { }

src/test/compile-fail/associated-types-no-suitable-bound.rs

@@ -19,7 +19,7 @@ struct Struct {
 
 impl Struct {
     fn uhoh<T>(foo: <T as Get>::Value) {}
-    //~^ ERROR the predicate `T : Get` is not satisfied
+    //~^ ERROR the trait bound `T : Get` is not satisfied
 }
 
 fn main() {