Return all impls, not just the primary one

Author: jyn514

Cargo.lock

@@ -4052,6 +4052,7 @@ dependencies = [
  "rustc-rayon",
  "serde",
  "serde_json",
+ "smallvec 1.4.0",
  "tempfile",
 ]
 

src/librustdoc/Cargo.toml

@@ -14,5 +14,6 @@ minifier = "0.0.33"
 rayon = { version = "0.3.0", package = "rustc-rayon" }
 serde = { version = "1.0", features = ["derive"] }
 serde_json = "1.0"
+smallvec = "1.0"
 tempfile = "3"
 itertools = "0.8"

src/librustdoc/clean/utils.rs

@@ -17,6 +17,7 @@ use rustc_middle::mir::interpret::{sign_extend, ConstValue, Scalar};
 use rustc_middle::ty::subst::{GenericArgKind, SubstsRef};
 use rustc_middle::ty::{self, DefIdTree, Ty, TyCtxt};
 use rustc_span::symbol::{kw, sym, Symbol};
+use smallvec::SmallVec;
 use std::mem;
 
 pub fn krate(mut cx: &mut DocContext<'_>) -> Crate {
@@ -349,11 +350,14 @@ pub fn qpath_to_string(p: &hir::QPath<'_>) -> String {
     s
 }
 
-pub fn impl_for_type(tcx: TyCtxt<'_>, primitive: PrimitiveType) -> Option<DefId> {
+pub fn impl_for_type(tcx: TyCtxt<'_>, primitive: PrimitiveType) -> SmallVec<[DefId; 4]> {
     use self::PrimitiveType::*;
 
+    let both =
+        |a: Option<DefId>, b: Option<DefId>| -> SmallVec<_> { a.into_iter().chain(b).collect() };
+
     let lang_items = tcx.lang_items();
-    match primitive {
+    let primary_impl = match primitive {
         Isize => lang_items.isize_impl(),
         I8 => lang_items.i8_impl(),
         I16 => lang_items.i16_impl(),
@@ -366,20 +370,38 @@ pub fn impl_for_type(tcx: TyCtxt<'_>, primitive: PrimitiveType) -> Option<DefId>
         U32 => lang_items.u32_impl(),
         U64 => lang_items.u64_impl(),
         U128 => lang_items.u128_impl(),
-        F32 => lang_items.f32_impl(),
-        F64 => lang_items.f64_impl(),
+        F32 => return both(lang_items.f32_impl(), lang_items.f32_runtime_impl()),
+        F64 => return both(lang_items.f64_impl(), lang_items.f64_runtime_impl()),
         Char => lang_items.char_impl(),
         Bool => lang_items.bool_impl(),
-        Str => lang_items.str_impl(),
-        Slice => lang_items.slice_impl(),
+        Str => return both(lang_items.str_impl(), lang_items.str_alloc_impl()),
+        Slice => {
+            return lang_items
+                .slice_impl()
+                .into_iter()
+                .chain(lang_items.slice_u8_impl())
+                .chain(lang_items.slice_alloc_impl())
+                .chain(lang_items.slice_u8_alloc_impl())
+                .collect();
+        }
         Array => lang_items.array_impl(),
         Tuple => None,
         Unit => None,
-        RawPointer => lang_items.const_ptr_impl(),
+        RawPointer => {
+            return lang_items
+                .const_ptr_impl()
+                .into_iter()
+                .chain(lang_items.mut_ptr_impl())
+                .chain(lang_items.const_slice_ptr_impl())
+                .chain(lang_items.mut_slice_ptr_impl())
+                .collect();
+        }
         Reference => None,
         Fn => None,
         Never => None,
-    }
+    };
+
+    primary_impl.into_iter().collect()
 }
 
 pub fn build_deref_target_impls(cx: &DocContext<'_>, items: &[Item], ret: &mut Vec<Item>) {
@@ -401,8 +423,7 @@ pub fn build_deref_target_impls(cx: &DocContext<'_>, items: &[Item], ret: &mut V
                 None => continue,
             },
         };
-        let did = impl_for_type(tcx, primitive);
-        if let Some(did) = did {
+        for did in impl_for_type(tcx, primitive) {
             if !did.is_local() {
                 inline::build_impl(cx, did, None, ret);
             }