get_template_directory(): string

337function get_template_directory() {338	$template     = get_template();339	$theme_root   = get_theme_root( $template );340	$template_dir = "$theme_root/$template";341 342	/**343	 * Filters the active theme directory path.344	 *345	 * @since 1.5.0346	 *347	 * @param string $template_dir The path of the active theme directory.348	 * @param string $template     Directory name of the active theme.349	 * @param string $theme_root   Absolute path to the themes directory.350	 */351	return apply_filters( 'template_directory', $template_dir, $template, $theme_root );352}