From 0a91daeaa33e4ae71e0be405cdddba741b72aa7f Mon Sep 17 00:00:00 2001
From: Rune Tynan <runetynan@gmail.com>
Date: Mon, 8 Feb 2021 16:04:14 -0500
Subject: [PATCH] Vec -> HashSet

---
 src/librustdoc/json/conversions.rs | 17 ++++++++++-------
 src/rustdoc-json-types/lib.rs      | 10 +++++-----
 2 files changed, 15 insertions(+), 12 deletions(-)

diff --git a/src/librustdoc/json/conversions.rs b/src/librustdoc/json/conversions.rs
index af44ab9868e..de0240f28f7 100644
--- a/src/librustdoc/json/conversions.rs
+++ b/src/librustdoc/json/conversions.rs
@@ -14,6 +14,7 @@ use rustdoc_json_types::*;
 use crate::clean;
 use crate::formats::item_type::ItemType;
 use crate::json::JsonRenderer;
+use std::collections::HashSet;
 
 impl JsonRenderer<'_> {
     pub(super) fn convert_item(&self, item: clean::Item) -> Option<Item> {
@@ -225,19 +226,19 @@ crate fn from_ctor_kind(struct_type: CtorKind) -> StructType {
     }
 }
 
-crate fn from_fn_header(header: &rustc_hir::FnHeader) -> Vec<Modifiers> {
-    let mut v = Vec::new();
+crate fn from_fn_header(header: &rustc_hir::FnHeader) -> HashSet<Modifiers> {
+    let mut v = HashSet::new();
 
     if let rustc_hir::Unsafety::Unsafe = header.unsafety {
-        v.push(Modifiers::Unsafe);
+        v.insert(Modifiers::Unsafe);
     }
 
     if let rustc_hir::IsAsync::Async = header.asyncness {
-        v.push(Modifiers::Async);
+        v.insert(Modifiers::Async);
     }
 
     if let rustc_hir::Constness::Const = header.constness {
-        v.push(Modifiers::Const);
+        v.insert(Modifiers::Const);
     }
 
     v
@@ -372,9 +373,11 @@ impl From<clean::BareFunctionDecl> for FunctionPointer {
         let clean::BareFunctionDecl { unsafety, generic_params, decl, abi } = bare_decl;
         FunctionPointer {
             header: if let rustc_hir::Unsafety::Unsafe = unsafety {
-                vec![Modifiers::Unsafe]
+                let mut hs = HashSet::new();
+                hs.insert(Modifiers::Unsafe);
+                hs
             } else {
-                vec![]
+                HashSet::new()
             },
             generic_params: generic_params.into_iter().map(Into::into).collect(),
             decl: decl.into(),
diff --git a/src/rustdoc-json-types/lib.rs b/src/rustdoc-json-types/lib.rs
index 20bae0f14a2..a2f323699c1 100644
--- a/src/rustdoc-json-types/lib.rs
+++ b/src/rustdoc-json-types/lib.rs
@@ -3,7 +3,7 @@
 //! These types are the public API exposed through the `--output-format json` flag. The [`Crate`]
 //! struct is the root of the JSON blob and all other items are contained within.
 
-use std::collections::HashMap;
+use std::collections::{HashMap, HashSet};
 use std::path::PathBuf;
 
 use serde::{Deserialize, Serialize};
@@ -282,7 +282,7 @@ pub enum StructType {
 }
 
 #[non_exhaustive]
-#[derive(Clone, Debug, Serialize, Deserialize, PartialEq)]
+#[derive(Clone, Debug, Serialize, Deserialize, PartialEq, Eq, Hash)]
 #[serde(rename_all = "snake_case")]
 pub enum Modifiers {
     Const,
@@ -294,7 +294,7 @@ pub enum Modifiers {
 pub struct Function {
     pub decl: FnDecl,
     pub generics: Generics,
-    pub header: Vec<Modifiers>,
+    pub header: HashSet<Modifiers>,
     pub abi: String,
 }
 
@@ -302,7 +302,7 @@ pub struct Function {
 pub struct Method {
     pub decl: FnDecl,
     pub generics: Generics,
-    pub header: Vec<Modifiers>,
+    pub header: HashSet<Modifiers>,
     pub abi: String,
     pub has_body: bool,
 }
@@ -415,7 +415,7 @@ pub enum Type {
 pub struct FunctionPointer {
     pub decl: FnDecl,
     pub generic_params: Vec<GenericParamDef>,
-    pub header: Vec<Modifiers>,
+    pub header: HashSet<Modifiers>,
     pub abi: String,
 }