Bump to v4.0.0.

internal/createBaseWrapper.js

@@ -0,0 +1,27 @@
+var createCtorWrapper = require('./createCtorWrapper');
+
+/** Used to compose bitmasks for wrapper metadata. */
+var BIND_FLAG = 1;
+
+/**
+ * Creates a function that wraps `func` to invoke it with the optional `this`
+ * binding of `thisArg`.
+ *
+ * @private
+ * @param {Function} func The function to wrap.
+ * @param {number} bitmask The bitmask of wrapper flags. See `createWrapper` for more details.
+ * @param {*} [thisArg] The `this` binding of `func`.
+ * @returns {Function} Returns the new wrapped function.
+ */
+function createBaseWrapper(func, bitmask, thisArg) {
+  var isBind = bitmask & BIND_FLAG,
+      Ctor = createCtorWrapper(func);
+
+  function wrapper() {
+    var fn = (this && this !== global && this instanceof wrapper) ? Ctor : func;
+    return fn.apply(isBind ? thisArg : this, arguments);
+  }
+  return wrapper;
+}
+
+module.exports = createBaseWrapper;