64-bit compatibility issue in muParserBase.h

[VioletGiraffe]

 void  Error(EErrorCodes a_iErrc, 
                int a_iPos = (int)mu::string_type::npos, // <--- This line doesn't look safe
                const string_type &a_strTok = string_type() ) const;

std::string::npos is size_type, it's a 64-bit value in 64-bit mode. The highlighted line truncates it to 32-bit signed int. It's probably not causing any actual runtime errors, but looks bad and causes a host of compiler warnings (remember, it's in .h file so a warning is emitted for every .cpp that includes it).

[beltoforion]

Should be -1 but it not really dangerous since strind::npos is defined to be -1. No truncation taking place.

[VioletGiraffe]

I see what you mean, agreed. But MSVC does complain about truncation; the warning itself should be enough reason to fix this piece of code, IMO, regardless of how justified the warning is.

[jschueller]

@beltoforion could you register the project on appveyor to enable msvc builds so we can actually see what's going on ? (https://www.appveyor.com/)

The appveyor configuration was added in #38 but not actually used. If you want I can set it up for you if you grant me the rights to the repository.

[giraldeau]

I registered the project in my account, but there is no automatic trigger.

https://ci.appveyor.com/project/giraldeau/muparser

[beltoforion]

Sorry, I have no idea what appveyyor is or does. Never used it before.
@jschueller i have added you as a collaborator so if you want to set it up feel free to do it.

[jschueller]

Great, I could enable Appveyor, see the new README.rst.
It seems I need admin rights on the repo too to enable Travis though.

[jschueller]

@VioletGiraffe what of msvc version did you use ? any special flags ?

[VioletGiraffe]

@jschueller: msvc 2017 (v141 toolset), /W4 flag.

[beltoforion]

@jschueller: giving admin rights does not seem to be so easy. Seems i need to create a new organization and transfer project ownership. (Something i would do if everything else fails)

I connected muparser to travis-ci can you access it there?

[jschueller]

Travis works properly, thanks.
Now I realize AppVeyor was only enabled on my fork and does not trigger builds from here. Could you do the same for AppVeyor ?

[beltoforion]

I added it to appveyor. Please check out if you see it.