Implemented JsonVariant comparisons with template friends

src/ArduinoJson.hpp

@@ -10,7 +10,6 @@
 #include "ArduinoJson/DynamicJsonBuffer.hpp"
 #include "ArduinoJson/JsonArray.hpp"
 #include "ArduinoJson/JsonObject.hpp"
-#include "ArduinoJson/JsonVariantComparisons.hpp"
 #include "ArduinoJson/StaticJsonBuffer.hpp"
 
 #include "ArduinoJson/Deserialization/JsonParserImpl.hpp"

src/ArduinoJson/Data/JsonVariantComparer.hpp

@@ -1,69 +0,0 @@
-// Copyright Benoit Blanchon 2014-2017
-// MIT License
-//
-// Arduino JSON library
-// https://bblanchon.github.io/ArduinoJson/
-// If you like this project, please add a star!
-
-#pragma once
-
-#include "../JsonVariantBase.hpp"
-#include "../StringTraits/StringTraits.hpp"
-#include "../TypeTraits/EnableIf.hpp"
-
-namespace ArduinoJson {
-namespace Internals {
-template <typename TComparand, typename Enable = void>
-struct JsonVariantComparer {};
-
-template <typename TString>
-struct JsonVariantComparer<
-    TString,
-    typename TypeTraits::EnableIf<TypeTraits::IsString<TString>::value>::type> {
-  template <typename TVariant>
-  static bool equals(const JsonVariantBase<TVariant> &variant,
-                     const TString &comparand) {
-    const char *value = variant.template as<const char *>();
-    return Internals::StringTraits<TString>::equals(comparand, value);
-  }
-};
-
-template <typename TComparand>
-struct JsonVariantComparer<
-    TComparand, typename TypeTraits::EnableIf<
-                    !TypeTraits::IsVariant<TComparand>::value &&
-                    !TypeTraits::IsString<TComparand>::value>::type> {
-  template <typename TVariant>
-  static bool equals(const JsonVariantBase<TVariant> &variant,
-                     const TComparand &comparand) {
-    return variant.template as<TComparand>() == comparand;
-  }
-};
-
-template <typename TVariant2>
-struct JsonVariantComparer<TVariant2,
-                           typename TypeTraits::EnableIf<
-                               TypeTraits::IsVariant<TVariant2>::value>::type> {
-  template <typename TVariant1>
-  static bool equals(const JsonVariantBase<TVariant1> &left,
-                     const TVariant2 &right) {
-    if (left.template is<bool>() && right.template is<bool>())
-      return left.template as<bool>() == right.template as<bool>();
-    if (left.template is<JsonInteger>() && right.template is<JsonInteger>())
-      return left.template as<JsonInteger>() ==
-             right.template as<JsonInteger>();
-    if (left.template is<JsonFloat>() && right.template is<JsonFloat>())
-      return left.template as<JsonFloat>() == right.template as<JsonFloat>();
-    if (left.template is<JsonArray>() && right.template is<JsonArray>())
-      return left.template as<JsonArray>() == right.template as<JsonArray>();
-    if (left.template is<JsonObject>() && right.template is<JsonObject>())
-      return left.template as<JsonObject>() == right.template as<JsonObject>();
-    if (left.template is<char *>() && right.template is<char *>())
-      return strcmp(left.template as<char *>(), right.template as<char *>()) ==
-             0;
-
-    return false;
-  }
-};
-}
-}

src/ArduinoJson/JsonArraySubscript.hpp

@@ -106,15 +106,16 @@ inline const JsonArraySubscript JsonArray::operator[](size_t index) const {
   return JsonArraySubscript(*const_cast<JsonArray*>(this), index);
 }
 
-template <typename TImplem>
-inline JsonArraySubscript JsonVariantBase<TImplem>::operator[](size_t index) {
-  return as<JsonArray>()[index];
+template <typename TImpl>
+inline JsonArraySubscript JsonVariantSubscripts<TImpl>::operator[](
+    size_t index) {
+  return impl()->template as<JsonArray>()[index];
 }
 
-template <typename TImplem>
-inline const JsonArraySubscript JsonVariantBase<TImplem>::operator[](
+template <typename TImpl>
+inline const JsonArraySubscript JsonVariantSubscripts<TImpl>::operator[](
     size_t index) const {
-  return as<JsonArray>()[index];
+  return impl()->template as<JsonArray>()[index];
 }
 
 }  // namespace ArduinoJson

src/ArduinoJson/JsonVariantBase.hpp

@@ -7,133 +7,17 @@
 
 #pragma once
 
-#include "Data/JsonVariantAs.hpp"
-#include "Polyfills/attributes.hpp"
+#include "JsonVariantCasts.hpp"
+#include "JsonVariantComparisons.hpp"
+#include "JsonVariantSubscripts.hpp"
 #include "Serialization/JsonPrintable.hpp"
 
 namespace ArduinoJson {
 
-// Forward declarations.
-class JsonArraySubscript;
-template <typename TKey>
-class JsonObjectSubscript;
-
 template <typename TImpl>
-class JsonVariantBase : public Internals::JsonPrintable<TImpl> {
- public:
-#if ARDUINOJSON_ENABLE_DEPRECATED
-  DEPRECATED("use as<JsonArray>() instead")
-  FORCE_INLINE JsonArray &asArray() const {
-    return as<JsonArray>();
-  }
-
-  DEPRECATED("use as<JsonObject>() instead")
-  FORCE_INLINE JsonObject &asObject() const {
-    return as<JsonObject>();
-  }
-
-  DEPRECATED("use as<char*>() instead")
-  FORCE_INLINE const char *asString() const {
-    return as<const char *>();
-  }
-#endif
-
-  // Gets the variant as an array.
-  // Returns a reference to the JsonArray or JsonArray::invalid() if the
-  // variant
-  // is not an array.
-  FORCE_INLINE operator JsonArray &() const {
-    return as<JsonArray &>();
-  }
-
-  // Gets the variant as an object.
-  // Returns a reference to the JsonObject or JsonObject::invalid() if the
-  // variant is not an object.
-  FORCE_INLINE operator JsonObject &() const {
-    return as<JsonObject &>();
-  }
-
-  template <typename T>
-  FORCE_INLINE operator T() const {
-    return as<T>();
-  }
-
-  template <typename T>
-  FORCE_INLINE const typename Internals::JsonVariantAs<T>::type as() const {
-    return impl()->template as<T>();
-  }
-
-  template <typename T>
-  FORCE_INLINE bool is() const {
-    return impl()->template is<T>();
-  }
-
-  // Mimics an array or an object.
-  // Returns the size of the array or object if the variant has that type.
-  // Returns 0 if the variant is neither an array nor an object
-  size_t size() const {
-    return as<JsonArray>().size() + as<JsonObject>().size();
-  }
-
-  // Mimics an array.
-  // Returns the element at specified index if the variant is an array.
-  // Returns JsonVariant::invalid() if the variant is not an array.
-  FORCE_INLINE const JsonArraySubscript operator[](size_t index) const;
-  FORCE_INLINE JsonArraySubscript operator[](size_t index);
-
-  // Mimics an object.
-  // Returns the value associated with the specified key if the variant is
-  // an object.
-  // Return JsonVariant::invalid() if the variant is not an object.
-  //
-  // const JsonObjectSubscript operator[](TKey) const;
-  // TKey = const std::string&, const String&
-  template <typename TString>
-  FORCE_INLINE typename TypeTraits::EnableIf<
-      Internals::StringTraits<TString>::has_equals,
-      const JsonObjectSubscript<const TString &> >::type
-  operator[](const TString &key) const {
-    return as<JsonObject>()[key];
-  }
-  //
-  // const JsonObjectSubscript operator[](TKey) const;
-  // TKey = const std::string&, const String&
-  template <typename TString>
-  FORCE_INLINE typename TypeTraits::EnableIf<
-      Internals::StringTraits<TString>::has_equals,
-      JsonObjectSubscript<const TString &> >::type
-  operator[](const TString &key) {
-    return as<JsonObject>()[key];
-  }
-  //
-  // JsonObjectSubscript operator[](TKey);
-  // TKey = const char*, const char[N], const FlashStringHelper*
-  template <typename TString>
-  FORCE_INLINE typename TypeTraits::EnableIf<
-      Internals::StringTraits<const TString *>::has_equals,
-      JsonObjectSubscript<const TString *> >::type
-  operator[](const TString *key) {
-    return as<JsonObject>()[key];
-  }
-  //
-  // JsonObjectSubscript operator[](TKey);
-  // TKey = const char*, const char[N], const FlashStringHelper*
-  template <typename TString>
-  FORCE_INLINE typename TypeTraits::EnableIf<
-      Internals::StringTraits<TString *>::has_equals,
-      const JsonObjectSubscript<const TString *> >::type
-  operator[](const TString *key) const {
-    return as<JsonObject>()[key];
-  }
-
- private:
-  const TImpl *impl() const {
-    return static_cast<const TImpl *>(this);
-  }
-};
-
-namespace TypeTraits {
-template <typename T>
-struct IsVariant : IsBaseOf<JsonVariantBase<T>, T> {};
-}
+class JsonVariantBase : public Internals::JsonPrintable<TImpl>,
+                        public JsonVariantCasts<TImpl>,
+                        public JsonVariantComparisons<TImpl>,
+                        public JsonVariantSubscripts<TImpl>,
+                        public TypeTraits::JsonVariantTag {};
 }

src/ArduinoJson/JsonVariantCasts.hpp

@@ -0,0 +1,60 @@
+// Copyright Benoit Blanchon 2014-2017
+// MIT License
+//
+// Arduino JSON library
+// https://bblanchon.github.io/ArduinoJson/
+// If you like this project, please add a star!
+
+#pragma once
+
+#include "Data/JsonVariantAs.hpp"
+#include "Polyfills/attributes.hpp"
+
+namespace ArduinoJson {
+
+template <typename TImpl>
+class JsonVariantCasts {
+ public:
+#if ARDUINOJSON_ENABLE_DEPRECATED
+  DEPRECATED("use as<JsonArray>() instead")
+  FORCE_INLINE JsonArray &asArray() const {
+    return impl()->template as<JsonArray>();
+  }
+
+  DEPRECATED("use as<JsonObject>() instead")
+  FORCE_INLINE JsonObject &asObject() const {
+    return impl()->template as<JsonObject>();
+  }
+
+  DEPRECATED("use as<char*>() instead")
+  FORCE_INLINE const char *asString() const {
+    return impl()->template as<const char *>();
+  }
+#endif
+
+  // Gets the variant as an array.
+  // Returns a reference to the JsonArray or JsonArray::invalid() if the
+  // variant
+  // is not an array.
+  FORCE_INLINE operator JsonArray &() const {
+    return impl()->template as<JsonArray &>();
+  }
+
+  // Gets the variant as an object.
+  // Returns a reference to the JsonObject or JsonObject::invalid() if the
+  // variant is not an object.
+  FORCE_INLINE operator JsonObject &() const {
+    return impl()->template as<JsonObject &>();
+  }
+
+  template <typename T>
+  FORCE_INLINE operator T() const {
+    return impl()->template as<T>();
+  }
+
+ private:
+  const TImpl *impl() const {
+    return static_cast<const TImpl *>(this);
+  }
+};
+}

src/ArduinoJson/JsonVariantComparisons.hpp

@@ -7,82 +7,138 @@
 
 #pragma once
 
-#include "Data/JsonVariantComparer.hpp"
+#include "StringTraits/StringTraits.hpp"
+#include "TypeTraits/EnableIf.hpp"
+#include "TypeTraits/IsVariant.hpp"
 
 namespace ArduinoJson {
-template <typename TVariant, typename TComparand>
-inline bool operator==(const JsonVariantBase<TVariant> &variant,
-                       TComparand comparand) {
-  return Internals::JsonVariantComparer<TComparand>::equals(variant, comparand);
-}
 
-template <typename TVariant, typename TComparand>
-inline typename TypeTraits::EnableIf<!TypeTraits::IsVariant<TComparand>::value,
-                                     bool>::type
-operator==(TComparand comparand, const JsonVariantBase<TVariant> &variant) {
-  return Internals::JsonVariantComparer<TComparand>::equals(variant, comparand);
-}
+template <typename TImpl>
+class JsonVariantComparisons {
+ public:
+  template <typename TComparand>
+  friend bool operator==(const JsonVariantComparisons &variant,
+                         TComparand comparand) {
+    return variant.equals(comparand);
+  }
 
-template <typename TVariant, typename TComparand>
-inline bool operator!=(const JsonVariantBase<TVariant> &variant,
-                       TComparand comparand) {
-  return !Internals::JsonVariantComparer<TComparand>::equals(variant,
-                                                             comparand);
-}
+  template <typename TComparand>
+  friend
+      typename TypeTraits::EnableIf<!TypeTraits::IsVariant<TComparand>::value,
+                                    bool>::type
+      operator==(TComparand comparand, const JsonVariantComparisons &variant) {
+    return variant.equals(comparand);
+  }
 
-template <typename TVariant, typename TComparand>
-inline typename TypeTraits::EnableIf<!TypeTraits::IsVariant<TComparand>::value,
-                                     bool>::type
-operator!=(TComparand comparand, const JsonVariantBase<TVariant> &variant) {
-  return !Internals::JsonVariantComparer<TComparand>::equals(variant,
-                                                             comparand);
-}
+  template <typename TComparand>
+  friend bool operator!=(const JsonVariantComparisons &variant,
+                         TComparand comparand) {
+    return !variant.equals(comparand);
+  }
 
-template <typename TVariant, typename TComparand>
-inline bool operator<=(const JsonVariantBase<TVariant> &left,
-                       TComparand right) {
-  return left.template as<TComparand>() <= right;
-}
+  template <typename TComparand>
+  friend
+      typename TypeTraits::EnableIf<!TypeTraits::IsVariant<TComparand>::value,
+                                    bool>::type
+      operator!=(TComparand comparand, const JsonVariantComparisons &variant) {
+    return !variant.equals(comparand);
+  }
 
-template <typename TVariant, typename TComparand>
-inline bool operator<=(TComparand comparand,
-                       const JsonVariantBase<TVariant> &variant) {
-  return comparand <= variant.template as<TComparand>();
-}
+  template <typename TComparand>
+  friend bool operator<=(const JsonVariantComparisons &left, TComparand right) {
+    return left.as<TComparand>() <= right;
+  }
 
-template <typename TVariant, typename TComparand>
-inline bool operator>=(const JsonVariantBase<TVariant> &variant,
-                       TComparand comparand) {
-  return variant.template as<TComparand>() >= comparand;
-}
+  template <typename TComparand>
+  friend bool operator<=(TComparand comparand,
+                         const JsonVariantComparisons &variant) {
+    return comparand <= variant.as<TComparand>();
+  }
 
-template <typename TVariant, typename TComparand>
-inline bool operator>=(TComparand comparand,
-                       const JsonVariantBase<TVariant> &variant) {
-  return comparand >= variant.template as<TComparand>();
-}
+  template <typename TComparand>
+  friend bool operator>=(const JsonVariantComparisons &variant,
+                         TComparand comparand) {
+    return variant.as<TComparand>() >= comparand;
+  }
 
-template <typename TVariant, typename TComparand>
-inline bool operator<(const JsonVariantBase<TVariant> &varian,
-                      TComparand comparand) {
-  return varian.template as<TComparand>() < comparand;
-}
+  template <typename TComparand>
+  friend bool operator>=(TComparand comparand,
+                         const JsonVariantComparisons &variant) {
+    return comparand >= variant.as<TComparand>();
+  }
 
-template <typename TVariant, typename TComparand>
-inline bool operator<(TComparand comparand,
-                      const JsonVariantBase<TVariant> &variant) {
-  return comparand < variant.template as<TComparand>();
-}
+  template <typename TComparand>
+  friend bool operator<(const JsonVariantComparisons &varian,
+                        TComparand comparand) {
+    return varian.as<TComparand>() < comparand;
+  }
 
-template <typename TVariant, typename TComparand>
-inline bool operator>(const JsonVariantBase<TVariant> &variant,
-                      TComparand comparand) {
-  return variant.template as<TComparand>() > comparand;
-}
+  template <typename TComparand>
+  friend bool operator<(TComparand comparand,
+                        const JsonVariantComparisons &variant) {
+    return comparand < variant.as<TComparand>();
+  }
 
-template <typename TVariant, typename TComparand>
-inline bool operator>(TComparand comparand,
-                      const JsonVariantBase<TVariant> &variant) {
-  return comparand > variant.template as<TComparand>();
-}
+  template <typename TComparand>
+  friend bool operator>(const JsonVariantComparisons &variant,
+                        TComparand comparand) {
+    return variant.as<TComparand>() > comparand;
+  }
+
+  template <typename TComparand>
+  friend bool operator>(TComparand comparand,
+                        const JsonVariantComparisons &variant) {
+    return comparand > variant.as<TComparand>();
+  }
+
+ private:
+  const TImpl *impl() const {
+    return static_cast<const TImpl *>(this);
+  }
+
+  template <typename T>
+  const typename Internals::JsonVariantAs<T>::type as() const {
+    return impl()->template as<T>();
+  }
+
+  template <typename T>
+  bool is() const {
+    return impl()->template is<T>();
+  }
+
+  template <typename TString>
+  typename TypeTraits::EnableIf<TypeTraits::IsString<TString>::value,
+                                bool>::type
+  equals(const TString &comparand) const {
+    const char *value = as<const char *>();
+    return Internals::StringTraits<TString>::equals(comparand, value);
+  }
+
+  template <typename TComparand>
+  typename TypeTraits::EnableIf<!TypeTraits::IsVariant<TComparand>::value &&
+                                    !TypeTraits::IsString<TComparand>::value,
+                                bool>::type
+  equals(const TComparand &comparand) const {
+    return as<TComparand>() == comparand;
+  }
+
+  template <typename TVariant2>
+  bool equals(const JsonVariantComparisons<TVariant2> &right) const {
+    using namespace Internals;
+    if (is<bool>() && right.template is<bool>())
+      return as<bool>() == right.template as<bool>();
+    if (is<JsonInteger>() && right.template is<JsonInteger>())
+      return as<JsonInteger>() == right.template as<JsonInteger>();
+    if (is<JsonFloat>() && right.template is<JsonFloat>())
+      return as<JsonFloat>() == right.template as<JsonFloat>();
+    if (is<JsonArray>() && right.template is<JsonArray>())
+      return as<JsonArray>() == right.template as<JsonArray>();
+    if (is<JsonObject>() && right.template is<JsonObject>())
+      return as<JsonObject>() == right.template as<JsonObject>();
+    if (is<char *>() && right.template is<char *>())
+      return strcmp(as<char *>(), right.template as<char *>()) == 0;
+
+    return false;
+  }
+};
 }

src/ArduinoJson/JsonVariantSubscripts.hpp

@@ -0,0 +1,89 @@
+// Copyright Benoit Blanchon 2014-2017
+// MIT License
+//
+// Arduino JSON library
+// https://bblanchon.github.io/ArduinoJson/
+// If you like this project, please add a star!
+
+#pragma once
+
+#include "Data/JsonVariantAs.hpp"
+#include "Polyfills/attributes.hpp"
+#include "StringTraits/StringTraits.hpp"
+#include "TypeTraits/EnableIf.hpp"
+
+namespace ArduinoJson {
+
+// Forward declarations.
+class JsonArraySubscript;
+template <typename TKey>
+class JsonObjectSubscript;
+
+template <typename TImpl>
+class JsonVariantSubscripts {
+ public:
+  // Mimics an array or an object.
+  // Returns the size of the array or object if the variant has that type.
+  // Returns 0 if the variant is neither an array nor an object
+  size_t size() const {
+    return impl()->template as<JsonArray>().size() +
+           impl()->template as<JsonObject>().size();
+  }
+
+  // Mimics an array.
+  // Returns the element at specified index if the variant is an array.
+  // Returns JsonVariant::invalid() if the variant is not an array.
+  FORCE_INLINE const JsonArraySubscript operator[](size_t index) const;
+  FORCE_INLINE JsonArraySubscript operator[](size_t index);
+
+  // Mimics an object.
+  // Returns the value associated with the specified key if the variant is
+  // an object.
+  // Return JsonVariant::invalid() if the variant is not an object.
+  //
+  // const JsonObjectSubscript operator[](TKey) const;
+  // TKey = const std::string&, const String&
+  template <typename TString>
+  FORCE_INLINE typename TypeTraits::EnableIf<
+      Internals::StringTraits<TString>::has_equals,
+      const JsonObjectSubscript<const TString &> >::type
+  operator[](const TString &key) const {
+    return impl()->template as<JsonObject>()[key];
+  }
+  //
+  // const JsonObjectSubscript operator[](TKey) const;
+  // TKey = const std::string&, const String&
+  template <typename TString>
+  FORCE_INLINE typename TypeTraits::EnableIf<
+      Internals::StringTraits<TString>::has_equals,
+      JsonObjectSubscript<const TString &> >::type
+  operator[](const TString &key) {
+    return impl()->template as<JsonObject>()[key];
+  }
+  //
+  // JsonObjectSubscript operator[](TKey);
+  // TKey = const char*, const char[N], const FlashStringHelper*
+  template <typename TString>
+  FORCE_INLINE typename TypeTraits::EnableIf<
+      Internals::StringTraits<const TString *>::has_equals,
+      JsonObjectSubscript<const TString *> >::type
+  operator[](const TString *key) {
+    return impl()->template as<JsonObject>()[key];
+  }
+  //
+  // JsonObjectSubscript operator[](TKey);
+  // TKey = const char*, const char[N], const FlashStringHelper*
+  template <typename TString>
+  FORCE_INLINE typename TypeTraits::EnableIf<
+      Internals::StringTraits<TString *>::has_equals,
+      const JsonObjectSubscript<const TString *> >::type
+  operator[](const TString *key) const {
+    return impl()->template as<JsonObject>()[key];
+  }
+
+ private:
+  const TImpl *impl() const {
+    return static_cast<const TImpl *>(this);
+  }
+};
+}

src/ArduinoJson/TypeTraits/IsVariant.hpp

@@ -0,0 +1,20 @@
+// Copyright Benoit Blanchon 2014-2017
+// MIT License
+//
+// Arduino JSON library
+// https://bblanchon.github.io/ArduinoJson/
+// If you like this project, please add a star!
+
+#pragma once
+
+#include "IsBaseOf.hpp"
+
+namespace ArduinoJson {
+namespace TypeTraits {
+
+class JsonVariantTag {};
+
+template <typename T>
+struct IsVariant : IsBaseOf<JsonVariantTag, T> {};
+}
+}