Examples of storing, passing and calling std::function objects using lambdas and std::bind.

The first example demonstrates a basic case and the second covers functions with parameters.

## Usage

The following command compiles, executes and removes the example.

## firstclass.cpp

```sh
c++ -o 1-firstclass 1-firstclass.cpp -std=c++11 \
    && ./1-firstclass \
    && rm 1-firstclass
```

## firstclass-with-params.cpp

```sh
c++ -o 2-firstclass-with-params 2-firstclass-with-params.cpp -std=c++11 \
    && ./2-firstclass-with-params \
    && rm 2-firstclass-with-params
```