Bump to v4.3.0.

isBuffer.js

@@ -0,0 +1,45 @@
+define(['./constant', './_root'], function(constant, root) {
+
+  /** Used as a safe reference for `undefined` in pre-ES5 environments. */
+  var undefined;
+
+  /** Used to determine if values are of the language type `Object`. */
+  var objectTypes = {
+    'function': true,
+    'object': true
+  };
+
+  /** Detect free variable `exports`. */
+  var freeExports = (objectTypes[typeof exports] && exports && !exports.nodeType) ? exports : null;
+
+  /** Detect free variable `module`. */
+  var freeModule = (objectTypes[typeof module] && module && !module.nodeType) ? module : null;
+
+  /** Detect the popular CommonJS extension `module.exports`. */
+  var moduleExports = (freeModule && freeModule.exports === freeExports) ? freeExports : null;
+
+  /** Built-in value references. */
+  var Buffer = moduleExports ? root.Buffer : undefined;
+
+  /**
+   * Checks if `value` is a buffer.
+   *
+   * @static
+   * @memberOf _
+   * @category Lang
+   * @param {*} value The value to check.
+   * @returns {boolean} Returns `true` if `value` is a buffer, else `false`.
+   * @example
+   *
+   * _.isBuffer(new Buffer(2));
+   * // => true
+   *
+   * _.isBuffer(new Uint8Array(2));
+   * // => false
+   */
+  var isBuffer = !Buffer ? constant(false) : function(value) {
+    return value instanceof Buffer;
+  };
+
+  return isBuffer;
+});