assertion failure on isalpha()

[Archie243]

Hey I'm attempting to debug my program in Visual Studio, but I keep getting an assertion failure when running isalpha() on the char 'I'/0xcc/-52.

I've no idea where this character is coming from, and if I copy the contents of my input file to another text file and read that, it all goes well.

Please help, I can't find anything about this random, seemingly default character.

The text I'm using starts "just the place"

[jsmith]

AFAIK isalpha should never assert. Are you sure that is what is going on?

what is the assertion failure you are getting?

[Bazzy]

Check that your file is not using some character encoding other that ASCII

_{From MSDN ( http://msdn.microsoft.com/en-us/library/xt82b8z8(VS.71).aspx ) :}

When used with a debug CRT library, isalpha will display a CRT assert if passed a parameter that isn't EOF or in the range of 0 through 0xFF. When used with a debug CRT library, isalpha will use the parameter as an index into an array, with undefined results if the parameter isn't EOF or in the range of 0 through 0xFF.

[firedraco]

The weird 'I' character is what shows up (in VC++) when there is garbage data in the string/stream. Make sure that your data is in there correctly and there is not extra garbage data in there (perhaps from copying a array in or something).

[z05DSL3A]

This may help:
Bug Check 0xCC: PAGE_FAULT_IN_FREED_SPECIAL_POOL
The PAGE_FAULT_IN_FREED_SPECIAL_POOL bug check has a value of 0x000000CC. This indicates that the system has referenced memory which was earlier freed.

[Archie243]

well according to the error the assertion comes from line 56 of istype.c, but I think this must be a default value VC++ puts in in debug mode, because in release mode it doesn't come up with the error, it just does nothing.

Is there anything wrong with my allocation line:

WordStream::inFile.get(lookingAt);
?