--- /dev/null
+'use strict';
+
+var keys = require('../keys')
+ , value = require('../valid-value')
+
+ , max = Math.max;
+
+module.exports = function (dest, src/*, …srcn*/) {
+ var error, i, l = max(arguments.length, 2), assign;
+ dest = Object(value(dest));
+ assign = function (key) {
+ try { dest[key] = src[key]; } catch (e) {
+ if (!error) error = e;
+ }
+ };
+ for (i = 1; i < l; ++i) {
+ src = arguments[i];
+ keys(src).forEach(assign);
+ }
+ if (error !== undefined) throw error;
+ return dest;
+};