functions.php

<?php
/**
 * Theme functions file.
 *
 * This file is used to bootstrap the theme.
 *
 * @package   Luxe
 * @author    Brett Mason <brettsmason@gmail.com>
 * @copyright Copyright (c) 2018, Brett Mason
 * @link      https://github.com/brettsmason/luxe
 * @license   http://www.gnu.org/licenses/old-licenses/gpl-2.0.html
 */

/**
 * Compatibility check.
 *
 * Check that the site meets the minimum requirements for the theme before
 * proceeding if this is a theme for public release. If building for a client
 * that meets these requirements, this code is unnecessary.
 */
if ( version_compare( $GLOBALS['wp_version'], '5.2', '<' ) || version_compare( PHP_VERSION, '5.6', '<' ) ) {
	require_once get_parent_theme_file_path( 'bootstrap/compat.php' );
	return;
}

/**
 * Bootstrap the theme.
 *
 * Load the bootstrap files. Note that autoloading should happen first so that
 * any classes/functions are available that we might need.
 */
require_once get_parent_theme_file_path( 'bootstrap/autoload.php' );
require_once get_parent_theme_file_path( 'bootstrap/app.php' );