Update error expectations

Author: KiChjang

src/test/compile-fail/issue-23046.rs

@@ -25,6 +25,6 @@ pub fn let_<'var, VAR, F: for<'v: 'var> Fn(Expr<'v, VAR>) -> Expr<'v, VAR>>
 
 fn main() {
     let ex = |x| {
-        let_(add(x,x), |y| { //~ ERROR unable to infer enough type information about `_`
+        let_(add(x,x), |y| { //~ ERROR unable to infer enough type information about `VAR`
             let_(add(x, x), |x|x)})};
 }

src/test/compile-fail/issue-5062.rs

@@ -9,4 +9,4 @@
 // except according to those terms.
 
 fn main() { format!("{:?}", None); }
-    //~^ ERROR unable to infer enough type information about `_` [E0282]
+    //~^ ERROR unable to infer enough type information about `T` [E0282]

src/test/compile-fail/issue-6458-2.rs

@@ -11,5 +11,5 @@
 fn main() {
     // Unconstrained type:
     format!("{:?}", None);
-    //~^ ERROR unable to infer enough type information about `_` [E0282]
+    //~^ ERROR unable to infer enough type information about `T` [E0282]
 }

src/test/compile-fail/issue-6458-3.rs

@@ -12,7 +12,7 @@ use std::mem;
 
 fn main() {
     mem::transmute(0);
-    //~^ ERROR unable to infer enough type information about `_` [E0282]
-    //~| NOTE cannot infer type for `_`
+    //~^ ERROR unable to infer enough type information about `U` [E0282]
+    //~| NOTE cannot infer type for `U`
     //~| NOTE type annotations or generic parameter binding
 }

src/test/compile-fail/issue-6458.rs

@@ -17,8 +17,8 @@ pub fn foo<State>(_: TypeWithState<State>) {}
 
 pub fn bar() {
    foo(TypeWithState(marker::PhantomData));
-   //~^ ERROR unable to infer enough type information about `_` [E0282]
-   //~| NOTE cannot infer type for `_`
+   //~^ ERROR unable to infer enough type information about `State` [E0282]
+   //~| NOTE cannot infer type for `State`
    //~| NOTE type annotations or generic parameter binding
 }
 

src/test/compile-fail/issue-7813.rs

@@ -10,7 +10,7 @@
 
 fn main() {
     let v = &[];
-    let it = v.iter(); //~ ERROR unable to infer enough type information about `_` [E0282]
-                       //~| NOTE cannot infer type for `_`
+    let it = v.iter(); //~ ERROR unable to infer enough type information about `T` [E0282]
+                       //~| NOTE cannot infer type for `T`
                        //~| NOTE type annotations or generic parameter binding
 }

src/test/compile-fail/method-ambig-one-trait-unknown-int-type.rs

@@ -32,7 +32,7 @@ impl foo for Vec<isize> {
 fn m1() {
     // we couldn't infer the type of the vector just based on calling foo()...
     let mut x = Vec::new();
-    //~^ ERROR unable to infer enough type information about `_` [E0282]
+    //~^ ERROR unable to infer enough type information about `T` [E0282]
     x.foo();
 }
 

src/test/compile-fail/traits-multidispatch-convert-ambig-dest.rs

@@ -34,8 +34,8 @@ where T : Convert<U>
 
 fn a() {
     test(22, std::default::Default::default());
-    //~^ ERROR unable to infer enough type information about `_` [E0282]
-    //~| NOTE cannot infer type for `_`
+    //~^ ERROR unable to infer enough type information about `U` [E0282]
+    //~| NOTE cannot infer type for `U`
     //~| NOTE type annotations or generic parameter binding
 }
 

src/test/compile-fail/unconstrained-none.rs

@@ -11,7 +11,7 @@
 // Issue #5062
 
 fn main() {
-    None; //~ ERROR unable to infer enough type information about `_` [E0282]
-          //~| NOTE cannot infer type for `_`
+    None; //~ ERROR unable to infer enough type information about `T` [E0282]
+          //~| NOTE cannot infer type for `T`
           //~| NOTE type annotations or generic parameter binding
 }

src/test/compile-fail/unconstrained-ref.rs

@@ -13,7 +13,7 @@ struct S<'a, T:'a> {
 }
 
 fn main() {
-    S { o: &None }; //~ ERROR unable to infer enough type information about `_` [E0282]
-                    //~| NOTE cannot infer type for `_`
+    S { o: &None }; //~ ERROR unable to infer enough type information about `T` [E0282]
+                    //~| NOTE cannot infer type for `T`
                     //~| NOTE type annotations or generic parameter binding
 }