Enable -Wunused-value

Summary: [Folly] Enable `-Wunused-value`.

Reviewed By: Orvid

Differential Revision: D7266246

fbshipit-source-id: dc9b85a5f8ce67802cc2fa94746a26529012ec22

folly/concurrency/test/ConcurrentHashMapTest.cpp

@@ -89,22 +89,18 @@ TEST(ConcurrentHashMap, MoveTest) {
 struct foo {
   static int moved;
   static int copied;
-  foo(foo&& o) noexcept {
-    (void*)&o;
+  foo(foo&&) noexcept {
     moved++;
   }
-  foo& operator=(foo&& o) {
-    (void*)&o;
+  foo& operator=(foo&&) {
     moved++;
     return *this;
   }
-  foo& operator=(const foo& o) {
-    (void*)&o;
+  foo& operator=(const foo&) {
     copied++;
     return *this;
   }
-  foo(const foo& o) {
-    (void*)&o;
+  foo(const foo&) {
     copied++;
   }
   foo() {}

folly/functional/test/ApplyTupleTest.cpp

@@ -272,10 +272,10 @@ TEST(ApplyTuple, MemberFunctionWithUniquePtr) {
   MemberFunc mf;
   mf.x = 234;
 
-  EXPECT_EQ(folly::applyTuple(&MemberFunc::getX,
-                              std::make_tuple(std::unique_ptr<MemberFunc>(
-                                  new MemberFunc(mf)))),
-            234);
+  EXPECT_EQ(
+      folly::applyTuple(&MemberFunc::getX,
+                        std::make_tuple(std::make_unique<MemberFunc>(mf))),
+      234);
 }
 
 TEST(ApplyTuple, Array) {

folly/io/async/ssl/OpenSSLUtils.cpp

@@ -48,8 +48,8 @@ bool OpenSSLUtils::getTLSMasterKey(
     return true;
   }
 #else
-  (SSL_SESSION*)session;
-  (MutableByteRange) keyOut;
+  (void)session;
+  (void)keyOut;
 #endif
   return false;
 }
@@ -65,8 +65,8 @@ bool OpenSSLUtils::getTLSClientRandom(
     return true;
   }
 #else
-  (SSL*)ssl;
-  (MutableByteRange) randomOut;
+  (void)ssl;
+  (void)randomOut;
 #endif
   return false;
 }

folly/test/AtomicLinkedListTest.cpp

@@ -51,8 +51,10 @@ TEST(AtomicIntrusiveLinkedList, Basic) {
     EXPECT_FALSE(list.empty());
 
     size_t id = 0;
-    list.sweep(
-        [&](TestIntrusiveObject* obj) mutable { EXPECT_EQ(++id, obj->id()); });
+    list.sweep([&](TestIntrusiveObject* obj) mutable {
+      ++id;
+      EXPECT_EQ(id, obj->id());
+    });
 
     EXPECT_TRUE(list.empty());
   }
@@ -65,8 +67,10 @@ TEST(AtomicIntrusiveLinkedList, Basic) {
     EXPECT_FALSE(list.empty());
 
     size_t id = 1;
-    list.sweep(
-        [&](TestIntrusiveObject* obj) mutable { EXPECT_EQ(++id, obj->id()); });
+    list.sweep([&](TestIntrusiveObject* obj) mutable {
+      ++id;
+      EXPECT_EQ(id, obj->id());
+    });
 
     EXPECT_TRUE(list.empty());
   }
@@ -82,7 +86,8 @@ TEST(AtomicIntrusiveLinkedList, ReverseSweep) {
   list.insertHead(&c);
   size_t next_expected_id = 3;
   list.reverseSweep([&](TestIntrusiveObject* obj) {
-    EXPECT_EQ(next_expected_id--, obj->id());
+    auto const expected = next_expected_id--;
+    EXPECT_EQ(expected, obj->id());
   });
   EXPECT_TRUE(list.empty());
   // Test that we can still insert
@@ -116,8 +121,10 @@ TEST(AtomicIntrusiveLinkedList, Move) {
   EXPECT_FALSE(list3.empty());
 
   size_t id = 0;
-  list3.sweep(
-      [&](TestIntrusiveObject* obj) mutable { EXPECT_EQ(++id, obj->id()); });
+  list3.sweep([&](TestIntrusiveObject* obj) mutable {
+    ++id;
+    EXPECT_EQ(id, obj->id());
+  });
 }
 
 TEST(AtomicIntrusiveLinkedList, Stress) {

folly/test/CachelinePaddedTest.cpp

@@ -42,7 +42,8 @@ struct alignas(alignment) SizedData {
   void doModifications() {
     size_t i = 0;
     for (auto& datum : data) {
-      EXPECT_EQ(static_cast<unsigned char>(i++), datum);
+      EXPECT_EQ(static_cast<unsigned char>(i), datum);
+      ++i;
       ++datum;
     }
   }
@@ -50,7 +51,8 @@ struct alignas(alignment) SizedData {
   ~SizedData() {
     size_t i = 1;
     for (auto& datum : data) {
-      EXPECT_EQ(static_cast<unsigned char>(i++), datum);
+      EXPECT_EQ(static_cast<unsigned char>(i), datum);
+      ++i;
     }
   }