# binary

(* → c) → (a, b → c)

## Function Parameters

(fn)
The function to wrap.

Returns (function) A new function wrapping `fn`. The new function is guaranteed to be of arity 2.

## Function Technical Explanation

Wraps a function of any arity (including nullary) in a function that accepts exactly 2 parameters.
Any extraneous parameters will not be passed to the supplied function.

## Examples
```javascript
var takesThreeArgs = function(a, b, c) {
  return [a, b, c];
};
takesThreeArgs.length; //=> 3
takesThreeArgs(1, 2, 3); //=> [1, 2, 3]

var takesTwoArgs = R.binary(takesThreeArgs);
takesTwoArgs.length; //=> 2
// Only 2 arguments are passed to the wrapped function
takesTwoArgs(1, 2, 3); //=> [1, 2, undefined]
```