From 9589f4c4bc06e4bc72f0e5a3501b18a871b0e9be Mon Sep 17 00:00:00 2001
From: Eric Niebler <eniebler@fb.com>
Date: Mon, 19 Dec 2016 15:12:31 -0800
Subject: [PATCH] rename ExpectedStorage::isThis to isSelfAssign so that the
 self-assign check in operator= works

Summary: This corrects an oversight in folly::Expected where self-assign was not being detected correctly due to a half-applied edit.

Reviewed By: yfeldblum

Differential Revision: D4348181

fbshipit-source-id: 710b25c4c6d7aeaaea50493ccc5788d875ec4c2e
---
 folly/Expected.h            |  2 +-
 folly/test/ExpectedTest.cpp | 30 ++++++++++++++++++++++++++++++
 2 files changed, 31 insertions(+), 1 deletion(-)

diff --git a/folly/Expected.h b/folly/Expected.h
index b4e63ee9..5e6666db 100644
--- a/folly/Expected.h
+++ b/folly/Expected.h
@@ -445,7 +445,7 @@ struct ExpectedStorage<Value, Error, StorageType::eUnion>
       this->which_ = Which::eError;
     }
   }
-  bool isThis(const ExpectedStorage* that) const {
+  bool isSelfAssign(const ExpectedStorage* that) const {
     return this == that;
   }
   constexpr bool isSelfAssign(const void*) const {
diff --git a/folly/test/ExpectedTest.cpp b/folly/test/ExpectedTest.cpp
index a10c9e86..92acd0c1 100644
--- a/folly/test/ExpectedTest.cpp
+++ b/folly/test/ExpectedTest.cpp
@@ -560,6 +560,36 @@ TEST(Expected, NoThrowMoveAssignable) {
       (std::is_nothrow_move_assignable<Expected<ThrowingBadness, E>>::value));
 }
 
+struct NoSelfAssign {
+  NoSelfAssign() = default;
+  NoSelfAssign(NoSelfAssign&&) = default;
+  NoSelfAssign(const NoSelfAssign&) = default;
+  NoSelfAssign& operator=(NoSelfAssign&& that) {
+    EXPECT_NE(this, &that);
+    return *this;
+  }
+  NoSelfAssign& operator=(const NoSelfAssign& that) {
+    EXPECT_NE(this, &that);
+    return *this;
+  }
+};
+
+#ifdef __GNUC__
+#pragma GCC diagnostic push
+#pragma GCC diagnostic ignored "-Wpragmas"
+#pragma GCC diagnostic ignored "-Wself-move"
+#endif
+
+TEST(Expected, NoSelfAssign) {
+  folly::Expected<NoSelfAssign, int> e {NoSelfAssign{}};
+  e = e; // @nolint
+  e = std::move(e); // @nolint
+}
+
+#ifdef __GNUC__
+#pragma GCC diagnostic pop
+#endif
+
 struct NoDestructor {};
 
 struct WithDestructor {
-- 
2.34.1