re WordPress.PHP.NoSilencedErrors.Discouraged
		wp_safe_redirect( $url, $status_code );
		exit();
	}

	/**
	 * Fallback for wp_sfe_redirect().
	 *
	 * @static
	 *
	 * @param string $url URL.
	 * @return string
	 */
	public static function wp_safe_redirect_fallback( $url ) {
		return home_url( '?w3tc_repeat=invalid' );
	}

	/**
	 * Detects post ID.
	 *
	 * @static
	 *
	 * @return int
	 */
	public static function detect_post_id() {
		global $posts, $comment_post_ID, $post_ID; // phpcs:ignore WordPress.NamingConventions.ValidVariableName.VariableNotSnakeCase

		$p_val = Util_Request::get_integer( 'p' );

		if ( $post_ID ) {
			return $post_ID;
		} elseif ( $comment_post_ID ) { // phpcs:ignore WordPress.NamingConventions.ValidVariableName.VariableNotSnakeCase
			return $comment_post_ID; // phpcs:ignore WordPress.NamingConventions.ValidVariableName.VariableNotSnakeCase
		} elseif ( ( is_single() || is_page() ) && is_array( $posts ) && isset( $posts[0]->ID ) ) {
			return $posts[0]->ID;
		} elseif ( isset( $posts->ID ) ) {
			return $posts->ID;
		} elseif ( ! empty( $p_val ) ) {
			return $p_val;
		}

		return 0;
	}

	/**
	 * Get W3TC instance id.
	 *
	 * @static
	 *
	 * @return int
	 */
	public static function instance_id() {
		if ( defined( 'W3TC_INSTANCE_ID' ) ) {
			return W3TC_INSTANCE_ID;
		}

		static $instance_id;

		if ( ! isset( $instance_id ) ) {
			$config      = Dispatcher::config();
			$instance_id = $config->get_integer( 'common.instance_id', 0 );
		}

		return $instance_id;
	}

	/**
	 * Get W3TC edition.
	 *
	 * @static
	 *
	 * @param Config $config Config.
	 * @return string
	 */
	public static function w3tc_edition( $config = null ) {
		if ( self::is_w3tc_pro( $config ) && self::is_w3tc_pro_dev() ) {
			return 'pro development';
		}

		if ( self::is_w3tc_pro( $config ) ) {
			return 'pro';
		}

		return 'community';
	}

	/**
	 * Is W3TC Pro.
	 *
	 * @static
	 *
	 * @param Config $config Config.
	 * @return bool
	 */
	public static function is_w3tc_pro( $config = null ) {
		if ( defined( 'W3TC_PRO' ) && W3TC_PRO ) {
			return true;
		}

		if ( defined( 'W3TC_ENTERPRISE' ) && W3TC_ENTERPRISE ) {
			return true;
		}

		if ( is_object( $config ) ) {
			$plugin_type = $config->get_string( 'plugin.type' );

			if ( 'pro' === $plugin_type || 'pro_dev' === $plugin_type ) {
				return true;
			}
		}

		return false;
	}

	/**
	 * Enable Pro Dev mode support.
	 *
	 * @static
	 *
	 * @return bool
	 */
	public static function is_w3tc_pro_dev() {
		return defined( 'W3TC_PRO_DEV_MODE' ) && W3TC_PRO_DEV_MODE;
	}

	/**
	 * Quotes regular expression string.
	 *
	 * @static
	 *
	 * @param string $string    String.
	 * @param string $delimiter Delimeter.
	 * @return string
	 */
	public static function preg_quote( $string, $delimiter = '~' ) {
		$string = preg_quote( $string, $delimiter );
		$string = strtr(
			$string,
			array( ' ' => '\ ' )
		);

		return $string;
	}

	/**
	 * Returns true if zlib output compression is enabled otherwise false.
	 *
	 * @static
	 *
	 * @return bool
	 */
	public static function is_zlib_enabled() {
		return self::to_boolean( ini_get( 'zlib.output_compression' ) );
	}

	/**
	 * Recursive strips slahes from the var.
	 *
	 * @static
	 *
	 * @param mixed $var Value.
	 * @return mixed
	 */
	public static function stripslashes( $var ) {
		if ( is_string( $var ) ) {
			return stripslashes( $var );
		} elseif ( is_array( $var ) ) {
			$var = array_map( array( '\W3TC\Util_Environment', 'stripslashes' ), $var );
		}

		return $var;
	}

	/**
	 * Checks if post should be flushed or not. Returns true if it should not be flushed.
	 *
	 * @static
	 *
	 * @param object $post Post object.
	 * @param string $module Which cache module to check against (pgcache, varnish, dbcache or objectcache).
	 * @param Config $config Config.
	 * @return bool
	 */
	public static function is_flushable_post( $post, $module, $config ) {
		if ( is_numeric( $post ) ) {
			$post = get_post( $post );
		}

		$post_status = array( 'publish' );

		/**
		 * Dont flush when we have post "attachment"
		 * its child of the post and is flushed always when post is published, while not changed in fact.
		 */
		$post_type = array( 'revision', 'attachment' );
		switch ( $module ) {
			case 'pgcache':
			case 'varnish':
			case 'posts':   // Means html content of post pages.
				if ( ! $config->get_boolean( 'pgcache.reject.logged' ) ) {
					$post_status[] = 'private';
				}
				break;
			case 'dbcache':
				if ( ! $config->get_boolean( 'dbcache.reject.logged' ) ) {
					$post_status[] = 'private';
				}
				break;
		}

		$flushable = is_object( $post ) && ! in_array( $post->post_type, $post_type, true ) && in_array( $post->post_status, $post_status, true );

		return apply_filters( 'w3tc_flushable_post', $flushable, $post, $module );
	}

	/**
	 * Checks if post belongs to a custom post type.
	 *
	 * @since 2.1.7
	 * @static
	 *
	 * @param object $post Post object.
	 * @return bool
	 */
	public static function is_custom_post_type( $post ) {
		$post_type = get_post_type_object( $post->post_type );

		// post type not found belongs to default post type(s).
		if ( empty( $post_type ) ) {
			return false;
		}

		// check if custom.
		if ( false === $post_type->_builtin ) {
			return true;
		}

		return false;
	}

	/**
	 * Converts value to boolean.
	 *
	 * @static
	 *
	 * @param mixed $value Value.
	 * @return bool
	 */
	public static function to_boolean( $value ) {
		if ( is_string( $value ) ) {
			switch ( strtolower( $value ) ) {
			case '+':
			case '1':
			case 'y':
			case 'on':
			case 'yes':
			case 'true':
			case 'enabled':
				return true;

			case '-':
			case '0':
			case 'n':
			case 'no':
			case 'off':
			case 'false':
			case 'disabled':
				return false;
			}
		}

		return (boolean) $value;
	}

	/**
	 * Returns the apache, nginx version.
	 *
	 * @static
	 *
	 * @return string
	 */
	public static function get_server_version() {
		$sig     = explode(
			'/',
			isset( $_SERVER['SERVER_SOFTWARE'] ) ?
				htmlspecialchars( stripslashes( $_SERVER['SERVER_SOFTWARE'] ) ) : '' // phpcs:ignore
		);
		$temp    = isset( $sig[1] ) ? explode( ' ', $sig[1] ) : array( '0' );
		$version = $temp[0];

		return $version;
	}

	/**
	 * Checks if current request is REST REQUEST.
	 *
	 * @static
	 */
	public static function is_rest_request( $url ) {
		if ( defined( 'REST_REQUEST' ) && REST_REQUEST )
			return true;

		// in case when called before constant is set
		// wp filters are not available in that case
		return preg_match( '~' . W3TC_WP_JSON_URI . '~', $url );
	}

	/**
	 * Reset microcache.
	 *
	 * @static
	 */
	public static function reset_microcache() {
		global $w3_current_blog_id;
		$w3_current_blog_id = null;

		self::$is_using_master_config = null;
	}

	/**
	 * Removes blank lines, trim values, removes duplicates, and sorts array.
	 *
	 * @since 2.4.3
	 *
	 * @param array $values Array of values.
	 *
	 * @return array
	 */
	public static function clean_array( $values ) {
		if ( ! empty( $values ) && is_array( $values ) ) {
			$values = array_unique(
				array_filter(
					array_map(
						'trim',
						$values
					),
					'strlen'
				)
			);
			sort( $values );
		}

		return $values;
	}

	/**
	 * Parses textarea setting value from string to array.
	 *
	 * @since 2.4.3
	 *
	 * @param string $value Value.
	 *
	 * @return array
	 */
	public static function textarea_to_array( $value ) {
		$values_array = array();

		if ( ! empty( $value ) ) {
			$values_array = self::clean_array(
				preg_split(
					'/\R/',
					$value,
					0,
					PREG_SPLIT_NO_EMPTY
				)
			);
		}

		return $values_array;
	}
}