Remove more anonymous trait method parameters

Author: petrochenkov

src/librustc/diagnostics.rs

@@ -614,7 +614,7 @@ use std::mem::transmute;
 struct Foo<T>(Vec<T>);
 
 trait MyTransmutableType: Sized {
-    fn transmute(Vec<Self>) -> Foo<Self>;
+    fn transmute(_: Vec<Self>) -> Foo<Self>;
 }
 
 impl MyTransmutableType for u8 {

src/librustc_resolve/diagnostics.rs

@@ -837,7 +837,7 @@ impl Something {} // ok!
 trait Foo {
     type N;
 
-    fn bar(Self::N); // ok!
+    fn bar(_: Self::N); // ok!
 }
 
 // or:

src/librustc_typeck/diagnostics.rs

@@ -2476,7 +2476,7 @@ trait T2 {
     type Bar;
 
     // error: Baz is used but not declared
-    fn return_bool(&self, &Self::Bar, &Self::Baz) -> bool;
+    fn return_bool(&self, _: &Self::Bar, _: &Self::Baz) -> bool;
 }
 ```
 
@@ -2498,7 +2498,7 @@ trait T2 {
     type Baz; // we declare `Baz` in our trait.
 
     // and now we can use it here:
-    fn return_bool(&self, &Self::Bar, &Self::Baz) -> bool;
+    fn return_bool(&self, _: &Self::Bar, _: &Self::Baz) -> bool;
 }
 ```
 "##,

src/test/compile-fail/associated-types-ICE-when-projecting-out-of-err.rs

@@ -25,7 +25,7 @@ pub trait Sized {
 trait Add<RHS=Self> {
     type Output;
 
-    fn add(self, RHS) -> Self::Output;
+    fn add(self, _: RHS) -> Self::Output;
 }
 
 fn ice<A>(a: A) {

src/test/compile-fail/issue-13853-5.rs

@@ -11,7 +11,7 @@
 trait Deserializer<'a> { }
 
 trait Deserializable {
-    fn deserialize_token<'a, D: Deserializer<'a>>(D, &'a str) -> Self;
+    fn deserialize_token<'a, D: Deserializer<'a>>(_: D, _: &'a str) -> Self;
 }
 
 impl<'a, T: Deserializable> Deserializable for &'a str {

src/test/compile-fail/issue-18400.rs

@@ -9,8 +9,8 @@
 // except according to those terms.
 
 trait Set<T> {
-    fn contains(&self, T) -> bool;
-    fn set(&mut self, T);
+    fn contains(&self, _: T) -> bool;
+    fn set(&mut self, _: T);
 }
 
 impl<'a, T, S> Set<&'a [T]> for S where

src/test/compile-fail/issue-20831-debruijn.rs

@@ -22,7 +22,7 @@ pub trait Subscriber {
 
 pub trait Publisher<'a> {
     type Output;
-    fn subscribe(&mut self, Box<Subscriber<Input=Self::Output> + 'a>);
+    fn subscribe(&mut self, _: Box<Subscriber<Input=Self::Output> + 'a>);
 }
 
 pub trait Processor<'a> : Subscriber + Publisher<'a> { }

src/test/compile-fail/issue-35869.rs

@@ -11,9 +11,9 @@
 #![feature(conservative_impl_trait)]
 
 trait Foo {
-    fn foo(fn(u8) -> ()); //~ NOTE type in trait
-    fn bar(Option<u8>); //~ NOTE type in trait
-    fn baz((u8, u16)); //~ NOTE type in trait
+    fn foo(_: fn(u8) -> ()); //~ NOTE type in trait
+    fn bar(_: Option<u8>); //~ NOTE type in trait
+    fn baz(_: (u8, u16)); //~ NOTE type in trait
     fn qux() -> u8; //~ NOTE type in trait
 }
 

src/test/compile-fail/type-params-in-different-spaces-2.rs

@@ -12,7 +12,7 @@
 // type parameters on a trait correctly.
 
 trait Tr<T> : Sized {
-    fn op(T) -> Self;
+    fn op(_: T) -> Self;
 }
 
 trait A:    Tr<Self> {

src/test/compile-fail/variance-trait-bounds.rs

@@ -19,7 +19,7 @@ trait Getter<T> {
 }
 
 trait Setter<T> {
-    fn get(&self, T);
+    fn get(&self, _: T);
 }
 
 #[rustc_variance]