rustdoc: Delete ReceiverTy (formerly known as SelfTy)

It was barely used, and the places that used it are actually clearer
without it since they were often undoing some of its work. This also
avoids an unnecessary clone of the receiver type and removes a layer of
logical indirection in the code.

Author: camelid

src/librustdoc/clean/types.rs

@@ -34,7 +34,6 @@ use thin_vec::ThinVec;
 use {rustc_ast as ast, rustc_hir as hir};
 
 pub(crate) use self::ItemKind::*;
-pub(crate) use self::ReceiverTy::*;
 pub(crate) use self::Type::{
     Array, BareFunction, BorrowedRef, DynTrait, Generic, ImplTrait, Infer, Primitive, QPath,
     RawPointer, SelfTy, Slice, Tuple,
@@ -1384,7 +1383,7 @@ pub(crate) struct FnDecl {
 }
 
 impl FnDecl {
-    pub(crate) fn receiver_type(&self) -> Option<ReceiverTy> {
+    pub(crate) fn receiver_type(&self) -> Option<&Type> {
         self.inputs.values.get(0).and_then(|v| v.to_receiver())
     }
 }
@@ -1403,27 +1402,9 @@ pub(crate) struct Argument {
     pub(crate) is_const: bool,
 }
 
-#[derive(Clone, PartialEq, Debug)]
-pub(crate) enum ReceiverTy {
-    SelfValue,
-    SelfBorrowed(Option<Lifetime>, Mutability),
-    SelfExplicit(Type),
-}
-
 impl Argument {
-    pub(crate) fn to_receiver(&self) -> Option<ReceiverTy> {
-        if self.name != kw::SelfLower {
-            return None;
-        }
-        if self.type_.is_self_type() {
-            return Some(SelfValue);
-        }
-        match self.type_ {
-            BorrowedRef { ref lifetime, mutability, ref type_ } if type_.is_self_type() => {
-                Some(SelfBorrowed(lifetime.clone(), mutability))
-            }
-            _ => Some(SelfExplicit(self.type_.clone())),
-        }
+    pub(crate) fn to_receiver(&self) -> Option<&Type> {
+        if self.name == kw::SelfLower { Some(&self.type_) } else { None }
     }
 }
 

src/librustdoc/html/format.rs

@@ -1455,27 +1455,20 @@ impl clean::FnDecl {
         for (i, input) in self.inputs.values.iter().enumerate() {
             if let Some(selfty) = input.to_receiver() {
                 match selfty {
-                    clean::SelfValue => {
+                    clean::SelfTy => {
                         write!(f, "self")?;
                     }
-                    clean::SelfBorrowed(Some(ref lt), mutability) => {
-                        write!(
-                            f,
-                            "{amp}{lifetime} {mutability}self",
-                            lifetime = lt.print(),
-                            mutability = mutability.print_with_space(),
-                        )?;
-                    }
-                    clean::SelfBorrowed(None, mutability) => {
-                        write!(
-                            f,
-                            "{amp}{mutability}self",
-                            mutability = mutability.print_with_space(),
-                        )?;
+                    clean::BorrowedRef { lifetime, mutability, type_: box clean::SelfTy } => {
+                        write!(f, "{amp}")?;
+                        match lifetime {
+                            Some(lt) => write!(f, "{lt} ", lt = lt.print())?,
+                            None => {}
+                        }
+                        write!(f, "{mutability}self", mutability = mutability.print_with_space())?;
                     }
-                    clean::SelfExplicit(ref typ) => {
+                    _ => {
                         write!(f, "self: ")?;
-                        typ.print(cx).fmt(f)?;
+                        selfty.print(cx).fmt(f)?;
                     }
                 }
             } else {

src/librustdoc/html/render/mod.rs

@@ -58,7 +58,7 @@ use serde::{Serialize, Serializer};
 
 pub(crate) use self::context::*;
 pub(crate) use self::span_map::{collect_spans_and_sources, LinkFromSrc};
-use crate::clean::{self, ItemId, ReceiverTy, RenderedLink};
+use crate::clean::{self, ItemId, RenderedLink};
 use crate::error::Error;
 use crate::formats::cache::Cache;
 use crate::formats::item_type::ItemType;
@@ -1378,15 +1378,14 @@ fn should_render_item(item: &clean::Item, deref_mut_: bool, tcx: TyCtxt<'_>) ->
     };
 
     if let Some(self_ty) = self_type_opt {
-        let (by_mut_ref, by_box, by_value) = match self_ty {
-            ReceiverTy::SelfBorrowed(_, mutability)
-            | ReceiverTy::SelfExplicit(clean::BorrowedRef { mutability, .. }) => {
+        let (by_mut_ref, by_box, by_value) = match *self_ty {
+            clean::Type::BorrowedRef { mutability, .. } => {
                 (mutability == Mutability::Mut, false, false)
             }
-            ReceiverTy::SelfExplicit(clean::Type::Path { path }) => {
+            clean::Type::Path { ref path } => {
                 (false, Some(path.def_id()) == tcx.lang_items().owned_box(), false)
             }
-            ReceiverTy::SelfValue => (false, false, true),
+            clean::Type::SelfTy => (false, false, true),
             _ => (false, false, false),
         };