C++ 17 style nested namespaces (#1326)

Summary:
X-link: https://github.com/facebook/react-native/pull/38304

Pull Request resolved: https://github.com/facebook/yoga/pull/1326

For better readability

Reviewed By: christophpurrer

Differential Revision: D47384926

fbshipit-source-id: 2f60d50a185331b3624d45d1fc45f98d504b3034

tests/BitUtilsTest.cpp

@@ -10,8 +10,7 @@
 #include <cstdint>
 #include <yoga/BitUtils.h>
 
-namespace facebook {
-namespace yoga {
+namespace facebook::yoga {
 
 TEST(BitUtils, one_boolean_defaults_to_false) {
   constexpr uint8_t flags = 0;
@@ -202,5 +201,4 @@ TEST(BitUtils, setting_values_does_not_spill_over) {
   ASSERT_EQ(detail::getEnumData<YGEdge>(flags, edgesOffset), 0xf);
 }
 
-} // namespace yoga
-} // namespace facebook
+} // namespace facebook::yoga

tests/EventsTest.cpp

@@ -18,9 +18,7 @@
 
 #include "util/TestUtil.h"
 
-namespace facebook {
-namespace yoga {
-namespace test {
+namespace facebook::yoga::test {
 
 template <Event::Type E>
 struct TypedEventTestData {};
@@ -353,6 +351,4 @@ void EventTest::TearDown() {
 
 std::vector<EventArgs> EventTest::events{};
 
-} // namespace test
-} // namespace yoga
-} // namespace facebook
+} // namespace facebook::yoga::test

tests/YGStyleAccessorsTest.cpp

@@ -76,8 +76,7 @@
     INDEX_ACCESSOR_TESTS(__VA_ARGS__)(NAME, IDX, __VA_ARGS__) \
   }
 
-namespace facebook {
-namespace yoga {
+namespace facebook::yoga {
 
 using CompactValue = detail::CompactValue;
 
@@ -255,5 +254,4 @@ ACCESSOR_TEST(
 
 #endif
 
-} // namespace yoga
-} // namespace facebook
+} // namespace facebook::yoga

tests/util/TestUtil.cpp

@@ -10,9 +10,7 @@
 #include <yoga/YGNode.h>
 #include <yoga/event/event.h>
 
-namespace facebook {
-namespace yoga {
-namespace test {
+namespace facebook::yoga::test {
 
 int nodeInstanceCount = 0;
 
@@ -61,6 +59,4 @@ ScopedEventSubscription::~ScopedEventSubscription() {
   Event::reset();
 }
 
-} // namespace test
-} // namespace yoga
-} // namespace facebook
+} // namespace facebook::yoga::test

tests/util/TestUtil.h

@@ -11,9 +11,7 @@
 
 #include <functional>
 
-namespace facebook {
-namespace yoga {
-namespace test {
+namespace facebook::yoga::test {
 
 struct YOGA_EXPORT TestUtil {
   static void startCountingNodes();
@@ -26,6 +24,4 @@ struct ScopedEventSubscription {
   ~ScopedEventSubscription();
 };
 
-} // namespace test
-} // namespace yoga
-} // namespace facebook
+} // namespace facebook::yoga::test