PSR-4 compliant autoloader for PHP7+

autoload.php

<?php

/**
 * PSR-4 compliant autoloader, updated for PHP7+
 *
 * @param $class
 */
spl_autoload_register( function( $class ) {
  require "vendor/autoload.php";
  if( defined( 'NAMESPACE_PREFIX' ) ) {
    $vendors[ NAMESPACE_PREFIX ] = "src";
  }
  foreach( $vendors as $prefix => $path ) {
    if( 0 === strpos( $class, $prefix ) ) {
      $basedir = __DIR__ . $path;
      $file = "{$basedir}/" . str_replace( "\\", "/", $class ) . ".php";
      if( is_readable( $file ) ) {
        require $file;
        break;
      }
    }
  }
} );