* @staticvar string $utf8_pcre

 *

	/**

	 * Compat function to mimic mb_substr().

	 *

	 * @ignore

	 * @since 3.2.0

	 *

	 * @see _mb_substr()

	 *

	 * @param string      $str      The string to extract the substring from.

	 * @param int         $start    Position to being extraction from in `$str`.

	 * @param int|null    $length   Optional. Maximum number of characters to extract from `$str`.

	 *                              Default null.

	 * @param string|null $encoding Optional. Character encoding to use. Default null.

	 * @return string Extracted substring.

	 */

/**

 * Internal compat function to mimic mb_substr().

 *

 *

 * @ignore

 * @since 3.2.0

 *

 * @param string      $str      The string to extract the substring from.

 * @param int         $start    Position to being extraction from in `$str`.

 * @param int|null    $length   Optional. Maximum number of characters to extract from `$str`.

 *                              Default null.

 * @param string|null $encoding Optional. Character encoding to use. Default null.

 * @return string Extracted substring.

	/*

	 * The solution below works only for UTF-8, so in case of a different

	 * charset just use built-in substr().

	 */

		// Use the regex unicode support to separate the UTF-8 characters into an array.

	// Start with 1 element instead of 0 since the first thing we do is pop.

	$chars = array( '' );

		/*

		 * Split by UTF-8 character, limit to 1000 characters (last array element will contain

		 * the rest of the string).

		 */

	// If there's anything left over, repeat the loop.

	} while ( count( $pieces ) > 1 && $str = array_pop( $pieces ) );

	/**

	 * Compat function to mimic mb_strlen().

	 *

	 * @ignore

	 * @since 4.2.0

	 *

	 * @see _mb_strlen()

	 *

	 * @param string      $str      The string to retrieve the character length from.

	 * @param string|null $encoding Optional. Character encoding to use. Default null.

	 * @return int String length of `$str`.

	 */

/**

 * Internal compat function to mimic mb_strlen().

 *

 * For $encoding === UTF-8, the `$str` input is expected to be a valid UTF-8 byte

 * sequence. The behavior of this function for invalid inputs is undefined.

 *

 * @ignore

 * @since 4.2.0

 *

 * @param string      $str      The string to retrieve the character length from.

 * @param string|null $encoding Optional. Character encoding to use. Default null.

 * @return int String length of `$str`.

	/*

	 * The solution below works only for UTF-8, so in case of a different charset

	 * just use built-in strlen().

	 */

		// Use the regex unicode support to separate the UTF-8 characters into an array.

	// Start at 1 instead of 0 since the first thing we do is decrement.

	$count = 1;

		/*

		 * Split by UTF-8 character, limit to 1000 characters (last array element will contain

		 * the rest of the string).

		 */

		// Increment.

	// If there's anything left over, repeat the loop.

	} while ( $str = array_pop( $pieces ) );

	// Fencepost: preg_split() always returns one extra item in the array.

/**

 * Compat function to mimic hash_hmac().

 *

 * @ignore

 * @since 3.2.0

 *

 * @see _hash_hmac()

 *

 * @param string $algo       Hash algorithm. Accepts 'md5' or 'sha1'.

 * @param string $data       Data to be hashed.

 * @param string $key        Secret key to use for generating the hash.

 * @param bool   $raw_output Optional. Whether to output raw binary data (true),

 *                           or lowercase hexits (false). Default false.

 * @return string|false The hash in output determined by `$raw_output`. False if `$algo`

 *                      is unknown or invalid.

 */

/**

 * Internal compat function to mimic hash_hmac().

 *

 * @ignore

 * @since 3.2.0

 *

 * @param string $algo       Hash algorithm. Accepts 'md5' or 'sha1'.

 * @param string $data       Data to be hashed.

 * @param string $key        Secret key to use for generating the hash.

 * @param bool   $raw_output Optional. Whether to output raw binary data (true),

 *                           or lowercase hexits (false). Default false.

 * @return string|false The hash in output determined by `$raw_output`. False if `$algo`

 *                      is unknown or invalid.

 */

	/**

	 * @global Services_JSON $wp_json

	 * @param string $string

	 * @param bool   $assoc_array

	 * @return object|array

	 */

	/**

	 * @param object $data

	 * @return array

	 */

 * Timing attack safe string comparison

 *

 * Compares two strings using the same time whether they're equal or not.

 *

 * Note: It can leak the length of a string when arguments of differing length are supplied.

 * @param string $b Actual, user supplied, string.

if ( ! function_exists( 'json_last_error_msg' ) ) :

	/**

	 * Retrieves the error string of the last json_encode() or json_decode() call.

	 *

	 * @since 4.4.0

	 *

	 * @internal This is a compatibility function for PHP <5.5

	 *

	 * @return bool|string Returns the error message on success, "No Error" if no error has occurred,

	 *                     or false on failure.

	 */

	function json_last_error_msg() {

		// See https://core.trac.wordpress.org/ticket/27799.

		if ( ! function_exists( 'json_last_error' ) ) {

			return false;

		}

		$last_error_code = json_last_error();

		// Just in case JSON_ERROR_NONE is not defined.

		$error_code_none = defined( 'JSON_ERROR_NONE' ) ? JSON_ERROR_NONE : 0;

		switch ( true ) {

			case $last_error_code === $error_code_none:

				return 'No error';

			case defined( 'JSON_ERROR_DEPTH' ) && JSON_ERROR_DEPTH === $last_error_code:

				return 'Maximum stack depth exceeded';

			case defined( 'JSON_ERROR_STATE_MISMATCH' ) && JSON_ERROR_STATE_MISMATCH === $last_error_code:

				return 'State mismatch (invalid or malformed JSON)';

			case defined( 'JSON_ERROR_CTRL_CHAR' ) && JSON_ERROR_CTRL_CHAR === $last_error_code:

				return 'Control character error, possibly incorrectly encoded';

			case defined( 'JSON_ERROR_SYNTAX' ) && JSON_ERROR_SYNTAX === $last_error_code:

				return 'Syntax error';

			case defined( 'JSON_ERROR_UTF8' ) && JSON_ERROR_UTF8 === $last_error_code:

				return 'Malformed UTF-8 characters, possibly incorrectly encoded';

			case defined( 'JSON_ERROR_RECURSION' ) && JSON_ERROR_RECURSION === $last_error_code:

				return 'Recursion detected';

			case defined( 'JSON_ERROR_INF_OR_NAN' ) && JSON_ERROR_INF_OR_NAN === $last_error_code:

				return 'Inf and NaN cannot be JSON encoded';

			case defined( 'JSON_ERROR_UNSUPPORTED_TYPE' ) && JSON_ERROR_UNSUPPORTED_TYPE === $last_error_code:

				return 'Type is not supported';

			default:

				return 'An unknown error occurred';

		}

	}

endif;

if ( ! interface_exists( 'JsonSerializable' ) ) {

	define( 'WP_JSON_SERIALIZE_COMPATIBLE', true );