From da9a588d4fda02c2fe6d52db651ec4c83b2b3e49 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Matthias=20Kr=C3=BCger?= <matthias.krueger@famsik.de>
Date: Sun, 21 Feb 2021 18:11:27 +0100
Subject: [PATCH] remove redundant wrapping of return types of
 allow_internal_unstable() and rustc_allow_const_fn_unstable()

---
 compiler/rustc_attr/src/builtin.rs                   | 8 ++++----
 compiler/rustc_expand/src/base.rs                    | 4 ++--
 compiler/rustc_mir/src/transform/check_consts/mod.rs | 3 +--
 compiler/rustc_passes/src/check_const.rs             | 2 +-
 4 files changed, 8 insertions(+), 9 deletions(-)

diff --git a/compiler/rustc_attr/src/builtin.rs b/compiler/rustc_attr/src/builtin.rs
index 378911f0c4e..24da75114a6 100644
--- a/compiler/rustc_attr/src/builtin.rs
+++ b/compiler/rustc_attr/src/builtin.rs
@@ -1035,15 +1035,15 @@ pub fn find_transparency(
 pub fn allow_internal_unstable<'a>(
     sess: &'a Session,
     attrs: &'a [Attribute],
-) -> Option<impl Iterator<Item = Symbol> + 'a> {
-    Some(allow_unstable(sess, attrs, sym::allow_internal_unstable))
+) -> impl Iterator<Item = Symbol> + 'a {
+    allow_unstable(sess, attrs, sym::allow_internal_unstable)
 }
 
 pub fn rustc_allow_const_fn_unstable<'a>(
     sess: &'a Session,
     attrs: &'a [Attribute],
-) -> Option<impl Iterator<Item = Symbol> + 'a> {
-    Some(allow_unstable(sess, attrs, sym::rustc_allow_const_fn_unstable))
+) -> impl Iterator<Item = Symbol> + 'a {
+    allow_unstable(sess, attrs, sym::rustc_allow_const_fn_unstable)
 }
 
 fn allow_unstable<'a>(
diff --git a/compiler/rustc_expand/src/base.rs b/compiler/rustc_expand/src/base.rs
index e3dc793a7fa..ca304c05cdc 100644
--- a/compiler/rustc_expand/src/base.rs
+++ b/compiler/rustc_expand/src/base.rs
@@ -756,8 +756,8 @@ impl SyntaxExtension {
         name: Symbol,
         attrs: &[ast::Attribute],
     ) -> SyntaxExtension {
-        let allow_internal_unstable = attr::allow_internal_unstable(sess, &attrs)
-            .map(|features| features.collect::<Vec<Symbol>>().into());
+        let allow_internal_unstable =
+            Some(attr::allow_internal_unstable(sess, &attrs).collect::<Vec<Symbol>>().into());
 
         let mut local_inner_macros = false;
         if let Some(macro_export) = sess.find_by_name(attrs, sym::macro_export) {
diff --git a/compiler/rustc_mir/src/transform/check_consts/mod.rs b/compiler/rustc_mir/src/transform/check_consts/mod.rs
index ba7bea4ac54..19aee033a69 100644
--- a/compiler/rustc_mir/src/transform/check_consts/mod.rs
+++ b/compiler/rustc_mir/src/transform/check_consts/mod.rs
@@ -85,8 +85,7 @@ pub fn rustc_allow_const_fn_unstable(
     feature_gate: Symbol,
 ) -> bool {
     let attrs = tcx.get_attrs(def_id);
-    attr::rustc_allow_const_fn_unstable(&tcx.sess, attrs)
-        .map_or(false, |mut features| features.any(|name| name == feature_gate))
+    attr::rustc_allow_const_fn_unstable(&tcx.sess, attrs).any(|name| name == feature_gate)
 }
 
 // Returns `true` if the given `const fn` is "const-stable".
diff --git a/compiler/rustc_passes/src/check_const.rs b/compiler/rustc_passes/src/check_const.rs
index 9328f7cd9ec..da713566c31 100644
--- a/compiler/rustc_passes/src/check_const.rs
+++ b/compiler/rustc_passes/src/check_const.rs
@@ -106,7 +106,7 @@ impl<'tcx> CheckConstVisitor<'tcx> {
             // However, we cannot allow stable `const fn`s to use unstable features without an explicit
             // opt-in via `rustc_allow_const_fn_unstable`.
             attr::rustc_allow_const_fn_unstable(&tcx.sess, &tcx.get_attrs(def_id))
-                .map_or(false, |mut features| features.any(|name| name == feature_gate))
+                .any(|name| name == feature_gate)
         };
 
         match required_gates {