Make impl associated constants sorted first

Author: GuillaumeGomez

src/librustdoc/html/render/mod.rs

@@ -1786,24 +1786,24 @@ fn render_impl(
 
     // Impl items are grouped by kinds:
     //
-    // 1. Types
-    // 2. Constants
+    // 1. Constants
+    // 2. Types
     // 3. Functions
     //
-    // This order is because you can have associated types in associated constants, and both in
-    // associcated functions. So with this order, when reading from top to bottom, you should always
-    // see all items definitions before they're actually used.
-    let mut assoc_consts = Vec::new();
+    // This order is because you can have associated constants used in associated types (like array
+    // length), and both in associcated functions. So with this order, when reading from top to
+    // bottom, you should see items definitions before they're actually used most of the time.
+    let mut assoc_types = Vec::new();
     let mut methods = Vec::new();
 
     if !impl_.is_negative_trait_impl() {
         for trait_item in &impl_.items {
             match *trait_item.kind {
                 clean::MethodItem(..) | clean::TyMethodItem(_) => methods.push(trait_item),
-                clean::TyAssocConstItem(..) | clean::AssocConstItem(_) => {
-                    assoc_consts.push(trait_item)
-                }
                 clean::TyAssocTypeItem(..) | clean::AssocTypeItem(..) => {
+                    assoc_types.push(trait_item)
+                }
+                clean::TyAssocConstItem(..) | clean::AssocConstItem(_) => {
                     // We render it directly since they're supposed to come first.
                     doc_impl_item(
                         &mut default_impl_items,
@@ -1822,12 +1822,12 @@ fn render_impl(
             }
         }
 
-        for assoc_const in assoc_consts {
+        for assoc_type in assoc_types {
             doc_impl_item(
                 &mut default_impl_items,
                 &mut impl_items,
                 cx,
-                assoc_const,
+                assoc_type,
                 if trait_.is_some() { &i.impl_item } else { parent },
                 link,
                 render_mode,

src/librustdoc/html/render/sidebar.rs

@@ -223,10 +223,10 @@ fn sidebar_trait<'a>(
     }
 
     let mut blocks: Vec<LinkBlock<'_>> = [
-        ("required-associated-types", "Required Associated Types", req_assoc),
-        ("provided-associated-types", "Provided Associated Types", prov_assoc),
         ("required-associated-consts", "Required Associated Constants", req_assoc_const),
         ("provided-associated-consts", "Provided Associated Constants", prov_assoc_const),
+        ("required-associated-types", "Required Associated Types", req_assoc),
+        ("provided-associated-types", "Provided Associated Types", prov_assoc),
         ("required-methods", "Required Methods", req_method),
         ("provided-methods", "Provided Methods", prov_method),
         ("foreign-impls", "Implementations on Foreign Types", foreign_impls),

tests/rustdoc/impl-associated-items-order.rs

@@ -1,7 +1,7 @@
 // This test ensures that impl associated items always follow this order:
 //
-// 1. Types
-// 2. Consts
+// 1. Consts
+// 2. Types
 // 3. Functions
 
 #![feature(inherent_associated_types)]
@@ -15,10 +15,10 @@ impl Bar {
     //@ has - '//*[@id="implementations-list"]//*[@class="impl-items"]/section[3]/h4' \
     // 'pub fn foo()'
     pub fn foo() {}
-    //@ has - '//*[@id="implementations-list"]//*[@class="impl-items"]/section[2]/h4' \
+    //@ has - '//*[@id="implementations-list"]//*[@class="impl-items"]/section[1]/h4' \
     // 'pub const X: u8 = 12u8'
     pub const X: u8 = 12;
-    //@ has - '//*[@id="implementations-list"]//*[@class="impl-items"]/section[1]/h4' \
+    //@ has - '//*[@id="implementations-list"]//*[@class="impl-items"]/section[2]/h4' \
     // 'pub type Y = u8'
     pub type Y = u8;
 }
@@ -31,11 +31,11 @@ pub trait Foo {
 
 impl Foo for Bar {
     //@ has - '//*[@id="trait-implementations-list"]//*[@class="impl-items"]/section[2]/h4' \
-    // 'const W: u32 = 12u32'
-    const W: u32 = 12;
-    //@ has - '//*[@id="trait-implementations-list"]//*[@class="impl-items"]/section[1]/h4' \
     // 'type Z = u8'
     type Z = u8;
+    //@ has - '//*[@id="trait-implementations-list"]//*[@class="impl-items"]/section[1]/h4' \
+    // 'const W: u32 = 12u32'
+    const W: u32 = 12;
     //@ has - '//*[@id="trait-implementations-list"]//*[@class="impl-items"]/section[3]/h4' \
     // 'fn yeay()'
     fn yeay() {}