Private routes with React Router v4

routes.js

function PrivateRoute ({component: Component, authenticated, ...rest}) {
  return (
    <Route
      {...rest}
      render={(props) => authenticated === true
        ? <Component {...props} />
        : <Redirect to={{pathname: '/login', state: {from: props.location}}} />}
    />
  )
}

<Route path='/' exact component={Home} />
<Route path='/login' component={Login} />
<Route path='/register' component={Register} />
<PrivateRoute authenticated={this.state.authenticated} path='/invoices' component={Invoices} />