Use nullptr rather than 0 for a null pointer

Summary: This time aided by clang-tidy's modernize-use-nullptr check.

Reviewed By: yfeldblum

Differential Revision: D6102739

fbshipit-source-id: aeb4bd0a8078d81cc88b766e0a034a37dd25fd1f

folly/AtomicHashArray-inl.h

@@ -414,18 +414,17 @@ struct AtomicHashArray<KeyT, ValueT, HashFcn, EqualFcn,
                              IterVal,
                              boost::forward_traversal_tag>
 {
-  explicit aha_iterator() : aha_(0) {}
+  explicit aha_iterator() : aha_(nullptr) {}
 
   // Conversion ctor for interoperability between const_iterator and
   // iterator.  The enable_if<> magic keeps us well-behaved for
   // is_convertible<> (v. the iterator_facade documentation).
   template <class OtherContT, class OtherVal>
-  aha_iterator(const aha_iterator<OtherContT,OtherVal>& o,
-               typename std::enable_if<
-               std::is_convertible<OtherVal*,IterVal*>::value >::type* = 0)
-      : aha_(o.aha_)
-      , offset_(o.offset_)
-  {}
+  aha_iterator(
+      const aha_iterator<OtherContT, OtherVal>& o,
+      typename std::enable_if<
+          std::is_convertible<OtherVal*, IterVal*>::value>::type* = nullptr)
+      : aha_(o.aha_), offset_(o.offset_) {}
 
   explicit aha_iterator(ContT* array, size_t offset)
       : aha_(array)

folly/AtomicHashMap-inl.h

@@ -468,19 +468,17 @@ struct AtomicHashMap<KeyT, ValueT, HashFcn, EqualFcn,
     ahm_iterator : boost::iterator_facade<ahm_iterator<ContT, IterVal, SubIt>,
                                           IterVal,
                                           boost::forward_traversal_tag> {
-  explicit ahm_iterator() : ahm_(0) {}
+  explicit ahm_iterator() : ahm_(nullptr) {}
 
   // Conversion ctor for interoperability between const_iterator and
   // iterator.  The enable_if<> magic keeps us well-behaved for
   // is_convertible<> (v. the iterator_facade documentation).
   template <class OtherContT, class OtherVal, class OtherSubIt>
-  ahm_iterator(const ahm_iterator<OtherContT,OtherVal,OtherSubIt>& o,
-               typename std::enable_if<
-               std::is_convertible<OtherSubIt,SubIt>::value >::type* = 0)
-      : ahm_(o.ahm_)
-      , subMap_(o.subMap_)
-      , subIt_(o.subIt_)
-  {}
+  ahm_iterator(
+      const ahm_iterator<OtherContT, OtherVal, OtherSubIt>& o,
+      typename std::enable_if<
+          std::is_convertible<OtherSubIt, SubIt>::value>::type* = nullptr)
+      : ahm_(o.ahm_), subMap_(o.subMap_), subIt_(o.subIt_) {}
 
   /*
    * Returns the unique index that can be used for access directly

folly/ConcurrentSkipList.h

@@ -676,9 +676,11 @@ class detail::csl_iterator :
   explicit csl_iterator(NodeT* node = nullptr) : node_(node) {}
 
   template <typename OtherVal, typename OtherNode>
-  csl_iterator(const csl_iterator<OtherVal, OtherNode> &other,
-      typename std::enable_if<std::is_convertible<OtherVal, ValT>::value>::type*
-      = 0) : node_(other.node_) {}
+  csl_iterator(
+      const csl_iterator<OtherVal, OtherNode>& other,
+      typename std::enable_if<
+          std::is_convertible<OtherVal, ValT>::value>::type* = nullptr)
+      : node_(other.node_) {}
 
   size_t nodeSize() const {
     return node_ == nullptr ? 0 :

folly/FBString.h

@@ -2333,7 +2333,7 @@ basic_fbstring<E, T, A, S>::find_first_of(
   }
   const_iterator i(begin() + pos), finish(end());
   for (; i != finish; ++i) {
-    if (traits_type::find(s, n, *i) != 0) {
+    if (traits_type::find(s, n, *i) != nullptr) {
       return i - begin();
     }
   }
@@ -2348,7 +2348,7 @@ basic_fbstring<E, T, A, S>::find_last_of(
     pos = std::min(pos, length() - 1);
     const_iterator i(begin() + pos);
     for (;; --i) {
-      if (traits_type::find(s, n, *i) != 0) {
+      if (traits_type::find(s, n, *i) != nullptr) {
         return i - begin();
       }
       if (i == begin()) {
@@ -2366,7 +2366,7 @@ basic_fbstring<E, T, A, S>::find_first_not_of(
   if (pos < length()) {
     const_iterator i(begin() + pos), finish(end());
     for (; i != finish; ++i) {
-      if (traits_type::find(s, n, *i) == 0) {
+      if (traits_type::find(s, n, *i) == nullptr) {
         return i - begin();
       }
     }
@@ -2382,7 +2382,7 @@ basic_fbstring<E, T, A, S>::find_last_not_of(
     pos = std::min(pos, size() - 1);
     const_iterator i(begin() + pos);
     for (;; --i) {
-      if (traits_type::find(s, n, *i) == 0) {
+      if (traits_type::find(s, n, *i) == nullptr) {
         return i - begin();
       }
       if (i == begin()) {

folly/Foreach.h

@@ -216,7 +216,7 @@ class HasLess {
   template <typename, typename> static BiggerThanChar test(...);
 
  public:
-  enum { value = sizeof(test<T, U>(0)) == 1 };
+  enum { value = sizeof(test<T, U>(nullptr)) == 1 };
 };
 
 /**

folly/LockTraits.h

@@ -106,11 +106,11 @@ class LockInterfaceDispatcher {
  public:
   static constexpr bool has_lock_unique = true;
   static constexpr bool has_lock_timed =
-      decltype(timed_lock_test<Mutex>(0))::value;
+      decltype(timed_lock_test<Mutex>(nullptr))::value;
   static constexpr bool has_lock_shared =
-      decltype(lock_shared_test<Mutex>(0))::value;
+      decltype(lock_shared_test<Mutex>(nullptr))::value;
   static constexpr bool has_lock_upgrade =
-      decltype(lock_upgrade_test<Mutex>(0))::value;
+      decltype(lock_upgrade_test<Mutex>(nullptr))::value;
 };
 
 /**

folly/small_vector.h

@@ -1137,7 +1137,7 @@ class small_vector : public detail::small_vector_base<
 
   union Data {
     explicit Data() {
-      pdata_.heap_ = 0;
+      pdata_.heap_ = nullptr;
     }
 
     PointerType pdata_;

folly/test/FBStringTest.cpp

@@ -1236,7 +1236,7 @@ TEST(FBString, testMoveOperatorPlusRhs) {
 //      other than libstdc++. Someday if we deem it important to present
 //      identical undefined behavior for other platforms, we can re-visit this.
 TEST(FBString, testConstructionFromLiteralZero) {
-  EXPECT_THROW(fbstring s(0), std::logic_error);
+  EXPECT_THROW(fbstring s(nullptr), std::logic_error);
 }
 
 TEST(FBString, testFixedBugs) {

folly/test/MPMCQueueTest.cpp

@@ -348,7 +348,7 @@ TEST(MPMCQueue, mt_try_enq_deq_deterministic) {
 
 uint64_t nowMicro() {
   timeval tv;
-  gettimeofday(&tv, 0);
+  gettimeofday(&tv, nullptr);
   return static_cast<uint64_t>(tv.tv_sec) * 1000000 + tv.tv_usec;
 }