--- /dev/null
+'use strict';
+
+var floor = Math.floor;
+
+module.exports = function (x) {
+ if (isNaN(x)) return NaN;
+ x = Number(x);
+ if (x === 0) return x;
+ if (x === Infinity) return Infinity;
+ if (x === -Infinity) return -Infinity;
+ if (x > 0) return floor(x);
+ return -floor(-x);
+};