Bump to v4.1.0.

_createRound.js

@@ -0,0 +1,30 @@
+import toInteger from './toInteger';
+import toNumber from './toNumber';
+import toString from './toString';
+
+/**
+ * Creates a function like `_.round`.
+ *
+ * @private
+ * @param {string} methodName The name of the `Math` method to use when rounding.
+ * @returns {Function} Returns the new round function.
+ */
+function createRound(methodName) {
+  var func = Math[methodName];
+  return function(number, precision) {
+    number = toNumber(number);
+    precision = toInteger(precision);
+    if (precision) {
+      // Shift with exponential notation to avoid floating-point issues.
+      // See [MDN](https://mdn.io/round#Examples) for more details.
+      var pair = (toString(number) + 'e').split('e'),
+          value = func(pair[0] + 'e' + (+pair[1] + precision));
+
+      pair = (toString(value) + 'e').split('e');
+      return +(pair[0] + 'e' + (+pair[1] - precision));
+    }
+    return func(number);
+  };
+}
+
+export default createRound;