if ((key->op_type != IS_UNUSED) && (key->u.EA.type & ZEND_PARSED_REFERENCE_VARIABLE)) {
//key不能以引用方式获取
zend_error(E_COMPILE_ERROR, "Key element cannot be a reference");
}
if (value->u.EA.type & ZEND_PARSED_REFERENCE_VARIABLE) {
//以引用方式获取值
assign_by_ref = 1;
if (!(opline-1)->extended_value) {
//根据FE_FETCH的上一条Opline也就是获取数组的扩展值来判断数组是否是匿名数组
zend_error(E_COMPILE_ERROR, "Cannot create references to elements of a temporary array expression");
}