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

yoga/BitUtils.h

@@ -13,10 +13,7 @@
 
 #include <yoga/YGEnums.h>
 
-namespace facebook {
-namespace yoga {
-
-namespace detail {
+namespace facebook::yoga::detail {
 
 // std::bitset with one bit for each option defined in YG_ENUM_SEQ_DECL
 template <typename Enum>
@@ -68,6 +65,4 @@ inline void setBooleanData(uint8_t& flags, size_t index, bool value) {
   }
 }
 
-} // namespace detail
-} // namespace yoga
-} // namespace facebook
+} // namespace facebook::yoga::detail

yoga/CompactValue.h

@@ -38,9 +38,7 @@ static_assert(
 #define VISIBLE_FOR_TESTING private:
 #endif
 
-namespace facebook {
-namespace yoga {
-namespace detail {
+namespace facebook::yoga::detail {
 
 // This class stores YGValue in 32 bits.
 // - The value does not matter for Undefined and Auto. NaNs are used for their
@@ -209,6 +207,4 @@ constexpr bool operator!=(CompactValue a, CompactValue b) noexcept {
   return !(a == b);
 }
 
-} // namespace detail
-} // namespace yoga
-} // namespace facebook
+} // namespace facebook::yoga::detail

yoga/YGConfig.cpp

@@ -9,16 +9,14 @@
 
 using namespace facebook::yoga;
 
-namespace facebook {
-namespace yoga {
+namespace facebook::yoga {
 bool configUpdateInvalidatesLayout(YGConfigRef a, YGConfigRef b) {
   return a->getErrata() != b->getErrata() ||
       a->getEnabledExperiments() != b->getEnabledExperiments() ||
       a->getPointScaleFactor() != b->getPointScaleFactor() ||
       a->useWebDefaults() != b->useWebDefaults();
 }
-} // namespace yoga
-} // namespace facebook
+} // namespace facebook::yoga
 
 YGConfig::YGConfig(YGLogger logger) : cloneNodeCallback_{nullptr} {
   setLogger(logger);

yoga/YGConfig.h

@@ -12,8 +12,7 @@
 #include "BitUtils.h"
 #include "Yoga-internal.h"
 
-namespace facebook {
-namespace yoga {
+namespace facebook::yoga {
 
 // Whether moving a node from config "a" to config "b" should dirty previously
 // calculated layout results.
@@ -48,8 +47,7 @@ struct YGConfigFlags {
 };
 #pragma pack(pop)
 
-} // namespace yoga
-} // namespace facebook
+} // namespace facebook::yoga
 
 struct YOGA_EXPORT YGConfig {
   YGConfig(YGLogger logger);

yoga/YGMacros.h

@@ -95,9 +95,8 @@
 #endif
 
 #ifdef __cplusplus
-namespace facebook {
-namespace yoga {
-namespace enums {
+
+namespace facebook::yoga::enums {
 
 template <typename T>
 constexpr int count(); // can't use `= delete` due to a defect in clang < 3.9
@@ -109,9 +108,7 @@ constexpr int n() {
 }
 } // namespace detail
 
-} // namespace enums
-} // namespace yoga
-} // namespace facebook
+} // namespace facebook::yoga::enums
 #endif
 
 #define YG_ENUM_DECL(NAME, ...)                               \
@@ -122,16 +119,13 @@ constexpr int n() {
 #define YG_ENUM_SEQ_DECL(NAME, ...)  \
   YG_ENUM_DECL(NAME, __VA_ARGS__)    \
   YG_EXTERN_C_END                    \
-  namespace facebook {               \
-  namespace yoga {                   \
-  namespace enums {                  \
+                                     \
+  namespace facebook::yoga::enums {  \
   template <>                        \
   constexpr int count<NAME>() {      \
     return detail::n<__VA_ARGS__>(); \
   }                                  \
   }                                  \
-  }                                  \
-  }                                  \
   YG_EXTERN_C_BEGIN
 #else
 #define YG_ENUM_SEQ_DECL YG_ENUM_DECL

yoga/YGNodePrint.cpp

@@ -16,8 +16,7 @@
 #include "Yoga-internal.h"
 #include "Utils.h"
 
-namespace facebook {
-namespace yoga {
+namespace facebook::yoga {
 typedef std::string string;
 
 static void indent(string& base, uint32_t level) {
@@ -242,6 +241,6 @@ void YGNodeToString(
   }
   appendFormattedString(str, "</div>");
 }
-} // namespace yoga
-} // namespace facebook
+
+} // namespace facebook::yoga
 #endif

yoga/YGNodePrint.h

@@ -13,8 +13,7 @@
 
 #include <yoga/Yoga.h>
 
-namespace facebook {
-namespace yoga {
+namespace facebook::yoga {
 
 void YGNodeToString(
     std::string& str,
@@ -22,7 +21,6 @@ void YGNodeToString(
     YGPrintOptions options,
     uint32_t level);
 
-} // namespace yoga
-} // namespace facebook
+} // namespace facebook::yoga
 
 #endif

yoga/Yoga-internal.h

@@ -33,8 +33,7 @@ void YGNodeDeallocate(YGNodeRef node);
 
 YG_EXTERN_C_END
 
-namespace facebook {
-namespace yoga {
+namespace facebook::yoga {
 
 inline bool isUndefined(float value) {
   return std::isnan(value);
@@ -46,8 +45,7 @@ inline bool isUndefined(double value) {
 
 void throwLogicalErrorWithMessage(const char* message);
 
-} // namespace yoga
-} // namespace facebook
+} // namespace facebook::yoga
 
 extern const std::array<YGEdge, 4> trailing;
 extern const std::array<YGEdge, 4> leading;
@@ -103,9 +101,7 @@ struct YGCachedMeasurement {
 // 98% of analyzed layouts require less than 8 entries.
 #define YG_MAX_CACHED_RESULT_COUNT 8
 
-namespace facebook {
-namespace yoga {
-namespace detail {
+namespace facebook::yoga::detail {
 
 template <size_t Size>
 class Values {
@@ -149,9 +145,8 @@ public:
 
   Values& operator=(const Values& other) = default;
 };
-} // namespace detail
-} // namespace yoga
-} // namespace facebook
+
+} // namespace facebook::yoga::detail
 
 static const float kDefaultFlexGrow = 0.0f;
 static const float kDefaultFlexShrink = 0.0f;

yoga/event/event.cpp

@@ -9,8 +9,7 @@
 #include <atomic>
 #include <memory>
 
-namespace facebook {
-namespace yoga {
+namespace facebook::yoga {
 
 const char* LayoutPassReasonToString(const LayoutPassReason value) {
   switch (value) {
@@ -82,5 +81,4 @@ void Event::publish(const YGNode& node, Type eventType, const Data& eventData) {
   }
 }
 
-} // namespace yoga
-} // namespace facebook
+} // namespace facebook::yoga

yoga/event/event.h

@@ -16,8 +16,7 @@
 struct YGConfig;
 struct YGNode;
 
-namespace facebook {
-namespace yoga {
+namespace facebook::yoga {
 
 enum struct LayoutType : int {
   kLayout = 0,
@@ -140,5 +139,4 @@ struct Event::TypedData<Event::NodeLayout> {
   void* layoutContext;
 };
 
-} // namespace yoga
-} // namespace facebook
+} // namespace facebook::yoga

yoga/log.cpp

@@ -11,9 +11,7 @@
 #include "YGConfig.h"
 #include "YGNode.h"
 
-namespace facebook {
-namespace yoga {
-namespace detail {
+namespace facebook::yoga::detail {
 
 namespace {
 
@@ -59,6 +57,4 @@ void Log::log(
   va_end(args);
 }
 
-} // namespace detail
-} // namespace yoga
-} // namespace facebook
+} // namespace facebook::yoga::detail

yoga/log.h

@@ -12,10 +12,7 @@
 struct YGNode;
 struct YGConfig;
 
-namespace facebook {
-namespace yoga {
-
-namespace detail {
+namespace facebook::yoga::detail {
 
 struct Log {
   static void log(
@@ -33,6 +30,4 @@ struct Log {
       ...) noexcept;
 };
 
-} // namespace detail
-} // namespace yoga
-} // namespace facebook
+} // namespace facebook::yoga::detail