Make sure to quality calls to std::swap. Otherwise, if a google::swap() exists…

Make sure to quality calls to std::swap.  Otherwise, if a google::swap() exists (e.g. because the user is using our own dense_hash_map implementation) it will be chosen instead, leading to a compile error.

src/google/protobuf/compiler/command_line_interface_unittest.cc

@@ -775,7 +775,7 @@ TEST_F(CommandLineInterfaceTest, WriteTransitiveDescriptorSet) {
   if (HasFatalFailure()) return;
   ASSERT_EQ(2, descriptor_set.file_size());
   if (descriptor_set.file(0).name() == "bar.proto") {
-    swap(descriptor_set.mutable_file()->mutable_data()[0],
+    std::swap(descriptor_set.mutable_file()->mutable_data()[0],
               descriptor_set.mutable_file()->mutable_data()[1]);
   }
   EXPECT_EQ("foo.proto", descriptor_set.file(0).name());

src/google/protobuf/generated_message_reflection.cc

@@ -324,7 +324,7 @@ void GeneratedMessageReflection::Swap(
   int has_bits_size = (descriptor_->field_count() + 31) / 32;
 
   for (int i = 0; i < has_bits_size; i++) {
-    swap(has_bits1[i], has_bits2[i]);
+    std::swap(has_bits1[i], has_bits2[i]);
   }
 
   for (int i = 0; i < descriptor_->field_count(); i++) {
@@ -360,7 +360,7 @@ void GeneratedMessageReflection::Swap(
       switch (field->cpp_type()) {
 #define SWAP_VALUES(CPPTYPE, TYPE)                                           \
         case FieldDescriptor::CPPTYPE_##CPPTYPE:                             \
-          swap(*MutableRaw<TYPE>(message1, field),                           \
+          std::swap(*MutableRaw<TYPE>(message1, field),                      \
                     *MutableRaw<TYPE>(message2, field));                     \
           break;
 
@@ -376,7 +376,7 @@ void GeneratedMessageReflection::Swap(
 #undef SWAP_VALUES
 
         case FieldDescriptor::CPPTYPE_STRING:
-            swap(*MutableRaw<string*>(message1, field),
+            std::swap(*MutableRaw<string*>(message1, field),
                       *MutableRaw<string*>(message2, field));
           break;
 

src/google/protobuf/repeated_field.h

@@ -491,7 +491,7 @@ void RepeatedField<Element>::Swap(RepeatedField* other) {
 
 template <typename Element>
 void RepeatedField<Element>::SwapElements(int index1, int index2) {
-  swap(elements_[index1], elements_[index2]);
+  std::swap(elements_[index1], elements_[index2]);
 }
 
 template <typename Element>
@@ -627,7 +627,7 @@ RepeatedPtrFieldBase::data() const {
 }
 
 inline void RepeatedPtrFieldBase::SwapElements(int index1, int index2) {
-  swap(elements_[index1], elements_[index2]);
+  std::swap(elements_[index1], elements_[index2]);
 }
 
 template <typename TypeHandler>