/* */ 
var assertFunction = require("./$.assert").fn;
module.exports = function(fn, that, length) {
  assertFunction(fn);
  if (~length && that === undefined)
    return fn;
  switch (length) {
    case 1:
      return function(a) {
        return fn.call(that, a);
      };
    case 2:
      return function(a, b) {
        return fn.call(that, a, b);
      };
    case 3:
      return function(a, b, c) {
        return fn.call(that, a, b, c);
      };
  }
  return function() {
    return fn.apply(that, arguments);
  };
};