--- /dev/null
+var aFunction = require('../internals/a-function');
+
+// optional / simple context binding
+module.exports = function (fn, that, length) {
+ aFunction(fn);
+ if (that === undefined) return fn;
+ switch (length) {
+ case 0: return function () {
+ return fn.call(that);
+ };
+ 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 (/* ...args */) {
+ return fn.apply(that, arguments);
+ };
+};