unyx / utils

        $funcIndexOf = $strict ? 'mb_strpos' : 'mb_stripos';

        // Find the offset of the first needle.

        if (false === $firstIndex = $funcIndexOf($haystack, $startNeedle, $offset, $encoding)) {

            throw new \OutOfBoundsException('Failed to find $startNeedle ['.$startNeedle.'] in $haystack ['.static::truncate($haystack, 20, '...', false, $encoding).'].');

        }

        // We're going to adjust the offset for the position of the first needle, ie. we're gonna

        // start searching for the second one right at the end of the first one.

        $offset = $firstIndex + mb_strlen($startNeedle, $encoding);

        // Find the offset of the second needle.

        if (false === $secondIndex = $funcIndexOf($haystack, $endNeedle, $offset, $encoding)) {

            throw new \OutOfBoundsException('Failed to find $endNeedle ['.$endNeedle.'] in $haystack ['.static::truncate($haystack, 20, '...', false, $encoding).'].');

        }

        // Return the substring between the needles.

        return mb_substr($haystack, $offset, $secondIndex - $offset);

        $func     = $strict ? 'mb_strstr' : 'mb_stristr';

        $encoding = $encoding ?: static::encoding($haystack);

        if (false === $result = $func($haystack, $needle, $before, $encoding)) {

            throw new \RuntimeException('Failed to find $needle ['.$needle.'] in $haystack ['.static::truncate($haystack, 20, '...', false, $encoding).'].');

        }

        return $result;

    }