[Info-vax] basic BASIC question

[Arne Vajhøj]

On 2/1/2025 6:38 PM, Craig A. Berry wrote:
> 
> On 2/1/25 3:00 PM, Arne Vajhøj wrote:
>> (in case someone wonder about C bool, then it is 8 bit!)
> 
> I don't think it has to be.  C99 says:
> 
> "An object declared as type _Bool is large enough to store the values 0
> and 1."
> 
> 8 bits are enough, but any integral type has enough bits.  "bool,"
> "true," and "false" in stdbool.h are macros that can be overridden,
> although doing so is described as "obsolescent" behavior.  It's probably
> necessary because of the uses of bool before the standard had it.
> 
> I'm pretty sure I've seen bool defined as an int on VMS, but whether
> that was something VAX C did for you or was just some what some program
> did in the absence of anything available from the (old) compiler I don't
> remember.

The C standard does not mandate 8 bit.

The VMS C documentation says 8 bit. Well - it says 1 byte
for whatever reason, but ...

<quote>
3.2. Integral Types
In C, an integral type can declare:

     Integer values, signed or unsigned

     Boolean values, where 0 is equivalent to false and any nonzero 
number is equivalent to true

     Characters, which are automatically converted to an integer value 
by the compiler

     Members of an enumerated type, which are interpreted as an integer 
by the compiler

     Bit fields

The integral types are:

     char, signed char, unsigned char – 8 bits

     short int, signed short int, and unsigned short int – 16 bits

     _Bool – 1 byte

     int, signed int, unsigned int – 32 bits

     long int, signed long int, and unsigned long int – 32 bits

     signed long long int and unsigned long long int – 64 bits

     signed __int64 and unsigned __int64 – 64 bits

     enum – 32 bits
</quote>

If one include stdbool.h then bool is _Bool. From C 99.

Before C 99 then I think:

typedef int bool;
#define TRUE 1
#define FALSE 0

was common.

(stdbool.h also defines true and false)

Arne