Twig_Environment::initOperators PHP Method

    protected function initOperators()
    {
        $this->unaryOperators = array();
        $this->binaryOperators = array();
        foreach ($this->getExtensions() as $extension) {
            $operators = $extension->getOperators();

            if (!$operators) {
                continue;
            }

            if (2 !== count($operators)) {
                throw new InvalidArgumentException(sprintf('"%s::getOperators()" does not return a valid operators array.', get_class($extension)));
            }

            $this->unaryOperators = array_merge($this->unaryOperators, $operators[0]);
            $this->binaryOperators = array_merge($this->binaryOperators, $operators[1]);
        }
    }