From bcf360a905b6a443d23ab0433ec64d79cc191cb6 Mon Sep 17 00:00:00 2001
From: Yedidya Feldblum <yfeldblum@fb.com>
Date: Mon, 22 Jun 2015 20:29:35 -0700
Subject: [PATCH] instance Eq Unit

Summary: [Folly] instance Eq Unit

    Unit::operator==(const Unit&)
    Unit::operator!=(const Unit&)

Reviewed By: @Gownta

Differential Revision: D2179384
---
 folly/futures/Unit.h            | 2 ++
 folly/futures/test/UnitTest.cpp | 8 ++++++++
 2 files changed, 10 insertions(+)

diff --git a/folly/futures/Unit.h b/folly/futures/Unit.h
index 9d67bf0f..44c3661b 100644
--- a/folly/futures/Unit.h
+++ b/folly/futures/Unit.h
@@ -29,6 +29,8 @@ struct Unit {
   template <class T> struct Lift : public std::false_type {
     using type = T;
   };
+  bool operator==(const Unit& other) const { return true; }
+  bool operator!=(const Unit& other) const { return false; }
 };
 
 // Lift void into Unit.
diff --git a/folly/futures/test/UnitTest.cpp b/folly/futures/test/UnitTest.cpp
index 965a830e..7e09a10b 100644
--- a/folly/futures/test/UnitTest.cpp
+++ b/folly/futures/test/UnitTest.cpp
@@ -26,6 +26,14 @@ TEST(Unit, futureDefaultCtor) {
   Future<Unit>();
 }
 
+TEST(Unit, operatorEq) {
+  EXPECT_TRUE(Unit{} == Unit{});
+}
+
+TEST(Unit, operatorNe) {
+  EXPECT_FALSE(Unit{} != Unit{});
+}
+
 TEST(Unit, voidOrUnit) {
   EXPECT_TRUE(is_void_or_unit<void>::value);
   EXPECT_TRUE(is_void_or_unit<Unit>::value);
-- 
2.34.1