Subj : Re: sscanf and bool
To   : borland.public.cpp.borlandcpp
From : Greg Chicares
Date : Tue Aug 24 2004 12:06 pm

Jogy wrote:
> MarvinAvery wrote:
> 
>> I have a character string that contains some boolean values: eg. "0010"
>> I want to read these values via the sscanf() function: eg.
>>     bool  b1, b2, b3, b4;
>>     sscanf (line, "%1d%1d%1d%1d", &b1, &b2, &b3, &b4);
>>
>> Problem is "%1d" stores the value as int -- that is as 16 bits whereas 
>> the
>> storage location is only 8 bits. So I am getting a buffer overflow.
>>
>> Is there any conversion format that will read and store an 8-bit integer?
>> Any other suggestions?

Avoid sscanf(): as your example shows, it's unsafe.
Do you need anything fancier than
   bool b0 = "0" != values[0]
   ...
   bool b3 = "0" != values[3]
after making sure you have exactly four characters to convert?

> I think %c is the printf/scanf format for 8-bit variable.

Isn't "%c" for one-byte characters?

> But I am not sure if the current C++ standard specifies that
> the size of bool is 8-bit .....

sizeof(bool) is implementation-defined: 5.3.3/1 .

.