src/Primitive/Support/Traits/RetrievableTrait.php
public function isStringable($value, $strict = false)
    {
        if ( ! $this->getBoolable($strict))
        {
            return  is_string($value) ||
                    is_array($value) ||
                    is_numeric($value) ||
                    is_bool($value) ||
                    $value instanceof StringContract ||
                    $value instanceof ContainerContract ||
                    $value instanceof ArrayableContract ||
                    (is_object($value) && method_exists($value, '__toString'));
        }

        return is_string($value) || $strict instanceof StringContract;
    }
public function isStringable($value, $strict = false)
    {
        if ( ! $this->getBoolable($strict))
        {
            return  is_string($value) ||
                    is_array($value) ||
                    is_numeric($value) ||
                    is_bool($value) ||
                    $value instanceof StringContract ||
                    $value instanceof ContainerContract ||
                    $value instanceof ArrayableContract ||
                    (is_object($value) && method_exists($value, '__toString'));
        }

        return is_string($value) || $strict instanceof StringContract;
    }
Check if $value is Stringable.
Second argument can be specified to check strict.

@param mixed $value
@param bool  $strict
@return bool