sample_ranged_hash_fn Interface

# `sample_ranged_hash_fn` Interface

A sample ranged-hash functor.

This class serves to show the interface a ranged-hash functor needs to support.

1. `sample_ranged_hash_fn.hpp`
2. Public Methods:
   1. Constructors, destructor, and related.

## Constructors, destructor, and related.

Method | Description
      sample_ranged_hash_fn
      ()
| Default constructor. Must be default constructible.
      sample_ranged_hash_fn
      (const sample_ranged_hash_fn &r_other)
| Copy constructor. Must be copy constructible.
    inline void
      swap
      (sample_ranged_hash_fn &r_other)
| Swaps content. Must be swappable (if there is such a word).