1 files changed, 82 insertions, 0 deletions
diff --git a/c++.html.markdown b/c++.html.markdown
index 2bee51dc..6b452b1b 100644
--- a/c++.html.markdown
+++ b/c++.html.markdown
@@ -310,6 +310,70 @@ basic_string(basic_string&& other);
 // constructor that "salvages" parts of that temporary string. You will see this
 // concept referred to as "move semantics".
 
+/////////////////////
+// Enums
+/////////////////////
+
+// Enums are a way to assign a value to a constant most commonly used for
+// easier visualization and reading of code
+enum ECarTypes
+{
+  Sedan,
+  Hatchback,
+  SUV,
+  Wagon
+};
+
+ECarTypes GetPreferredCarType()
+{
+	return ECarTypes::Hatchback;
+}
+
+// As of C++11 there is an easy way to assign a type to the enum which can be
+// useful in serialization of data and converting enums back-and-forth between 
+// the desired type and their respective constants
+enum ECarTypes : uint8_t
+{
+  Sedan, // 0
+  Hatchback, // 1
+  SUV = 254, // 254
+  Hybrid // 255
+};
+
+void WriteByteToFile(uint8_t InputValue)
+{
+	// Serialize the InputValue to a file
+}
+
+void WritePreferredCarTypeToFile(ECarTypes InputCarType)
+{
+	// The enum is implicitly converted to a uint8_t due to its declared enum type
+	WriteByteToFile(InputCarType);
+}
+
+// On the other hand you may not want enums to be accidentally cast to an integer
+// type or to other enums so it is instead possible to create an enum class which 
+// won't be implicitly converted
+enum class ECarTypes : uint8_t
+{
+  Sedan, // 0
+  Hatchback, // 1
+  SUV = 254, // 254
+  Hybrid // 255
+};
+
+void WriteByteToFile(uint8_t InputValue)
+{
+	// Serialize the InputValue to a file
+}
+
+void WritePreferredCarTypeToFile(ECarTypes InputCarType)
+{
+	// Won't compile even though ECarTypes is a uint8_t due to the enum
+	// being declared as an "enum class"!
+	WriteByteToFile(InputCarType);
+}
+
 //////////////////////////////////////////
 // Classes and object-oriented programming
 //////////////////////////////////////////
@@ -737,6 +801,24 @@ void doSomethingWithAFile(const std::string& filename)
 //   all automatically destroy their contents when they fall out of scope.
 // - Mutexes using lock_guard and unique_lock
 
+// containers with object keys of non-primitive values (custom classes) require
+// compare function in the object itself or as a function pointer. Primitives
+// have default comparators, but you can override it.
+class Foo {
+public:
+	int j;
+	Foo(int a) : j(a) {}
+};
+struct compareFunction {
+    bool operator()(const Foo& a, const Foo& b) const {
+        return a.j < b.j;
+    }
+};
+//this isn't allowed (although it can vary depending on compiler)
+//std::map<Foo, int> fooMap;
+std::map<Foo, int, compareFunction> fooMap;
+fooMap[Foo(1)]  = 1;
+fooMap.find(Foo(1)); //true
 
 /////////////////////
 // Fun stuff