added std::begin/end (#69)

* added std::begin/end

CPP11.md

@@ -49,6 +49,7 @@ C++11 includes the following new library features:
 - [std::make_shared](#stdmake_shared)
 - [memory model](#memory-model)
 - [std::async](#stdasync)
+- [std::begin/end](#stdbeginend)
 
 ## C++11 Language Features
 
@@ -874,6 +875,23 @@ auto handle = std::async(std::launch::async, foo);  // create an async task
 auto result = handle.get();  // wait for the result
 ```
 
+### std::begin/end
+`std::begin` and `std::end` free functions were added to return begin and end iterators of a container generically. These functions also work with raw arrays which do not have begin and end member functions.
+
+```c++
+template <typename T>
+int CountTwos(const T& container) {
+  return std::count_if(std::begin(container), std::end(container), [](int item) {
+    return item == 2;
+  });
+}
+
+std::vector<int> vec = {2,2,43,435,4543,534};
+int arr[8] = {2,43,45,435,32,32,32,32};
+auto a = CountTwos(vec); // 2
+auto b = CountTwos(arr);  // 1
+```
+
 ## Acknowledgements
 * [cppreference](http://en.cppreference.com/w/cpp) - especially useful for finding examples and documentation of new library features.
 * [C++ Rvalue References Explained](http://thbecker.net/articles/rvalue_references/section_01.html) - a great introduction I used to understand rvalue references, perfect forwarding, and move semantics.

README.md

@@ -98,6 +98,7 @@ C++11 includes the following new library features:
 - [std::make_shared](#stdmake_shared)
 - [memory model](#memory-model)
 - [std::async](#stdasync)
+- [std::begin/end](#stdbeginend)
 
 ## C++20 Language Features
 
@@ -1698,6 +1699,23 @@ auto handle = std::async(std::launch::async, foo);  // create an async task
 auto result = handle.get();  // wait for the result
 ```
 
+### std::begin/end
+`std::begin` and `std::end` free functions were added to return begin and end iterators of a container generically. These functions also work with raw arrays which do not have begin and end member functions.
+
+```c++
+template <typename T>
+int CountTwos(const T& container) {
+  return std::count_if(std::begin(container), std::end(container), [](int item) {
+    return item == 2;
+  });
+}
+
+std::vector<int> vec = {2,2,43,435,4543,534};
+int arr[8] = {2,43,45,435,32,32,32,32};
+auto a = CountTwos(vec); // 2
+auto b = CountTwos(arr);  // 1
+```
+
 ## Acknowledgements
 * [cppreference](http://en.cppreference.com/w/cpp) - especially useful for finding examples and documentation of new library features.
 * [C++ Rvalue References Explained](http://thbecker.net/articles/rvalue_references/section_01.html) - a great introduction I used to understand rvalue references, perfect forwarding, and move semantics.