if (PHP_VERSION_ID < 70000) {

    if (!is_callable('sodiumCompatAutoloader')) {

        /**

         * Sodium_Compat autoloader.

         *

         * @param string $class Class name to be autoloaded.

         *

         * @return bool         Stop autoloading?

         */

        function sodiumCompatAutoloader($class)

        {

            $namespace = 'ParagonIE_Sodium_';

            // Does the class use the namespace prefix?

            $len = strlen($namespace);

            if (strncmp($namespace, $class, $len) !== 0) {

                // no, move to the next registered autoloader

                return false;

            }

            // Get the relative class name

            $relative_class = substr($class, $len);

            // Replace the namespace prefix with the base directory, replace namespace

            // separators with directory separators in the relative class name, append

            // with .php

            $file = dirname(__FILE__) . '/src/' . str_replace('_', '/', $relative_class) . '.php';

            // if the file exists, require it

            if (file_exists($file)) {

                require_once $file;

                return true;

            }

        // Now that we have an autoloader, let's register it!

        spl_autoload_register('sodiumCompatAutoloader');

} else {

    require_once dirname(__FILE__) . '/autoload-php7.php';

/* Explicitly, always load the Compat class: */

require_once dirname(__FILE__) . '/src/Compat.php';

if (!class_exists('SodiumException', false)) {

    require_once dirname(__FILE__) . '/src/SodiumException.php';

}

    require_once(dirname(__FILE__) . '/lib/php72compat.php');

} elseif (!function_exists('sodium_crypto_stream_xchacha20_xor')) {

    // Older versions of {PHP, ext/sodium} will not define these

    require_once(dirname(__FILE__) . '/lib/php72compat.php');

require_once(dirname(__FILE__) . '/lib/ristretto255.php');