Re: [Jsoncpp-devel] Backwards incompatible change in jsoncpp 64-bit support

[Baptiste L. <bap...@gm...>]

I think you put your finger on something missing in the API.

I propose making the following changes:
1) isUInt() returns true only asUInt() can succeed. Similar changes for
isInt().
    I think this contract should be generalized. e.g. asUInt() should
succeed if the value is a positive signed int Value.
2) Adds new member functions:
   isUInt64() that returns true only if asUInt64() can succeed.
   and isInt64()...

If I understood your problem correctly, this should solve your backward
compatibility issue. Is that correct?

What do you think of this proposal?

Baptiste.

2011/5/23 Aaron Jacobs <ja...@go...>

> Hi all,
>
> I'm working on updating Google's internal version of jsoncpp from an
> ancient
> commit to the most recent version (SVN rev 192), but having some trouble. I
> think I've run into a backwards incompatible change that makes it nearly
> impossible for us to upgrade.
>
> In particular, there's jsoncpp-using code that looks something like this:
>
>    Json::Value value = ...
>    unsigned int value =
>        value.isUInt() ? value.asUInt() :
>            (value.isDouble() ? value.asDouble() : kError);
>
> That is, the code uses the isFoo methods to decide which asFoo method to
> call.
> The problem is that at SVN rev 192, values parsed as integers greater than
> 2^32 will return true for isUInt(), but have an assertion failure for
> asUInt():
>
>    value_.uint_ <= maxUInt
>    "unsigned integer out of UInt range"
>
> You can see this by parsing the string "31121983701778432", for example.
>
> As far as I can tell, there's no way for me to update to the latest version
> of
> jsoncpp without either changing the code above or breaking it (introducing
> incorrectness or a crasher bug into production). Updating the code is not
> an
> option for me since there is too much of it.
>
> Do you have any advice? In particular, am I missing something in the
> Json::Value API?
>
> Thanks,
> Aaron
>