Thread: Is bool a good thing?

It feels to me as though bool is a fundamental data type for computer programming. Storing true or false has obvious practical applications. Yet, some people seem to deprecate bool. It isn't in standard C89. And in any case, bool can be pretty easily simulated like this:

Code:

typedef bool unsigned int;
#define true 1
#define false 0

I'd like to use something like this:

Code:

typedef enum blah { false = 0, true = 1 } bool;

1. Do you consider bool to be a useful and necessary data type?
2. How does one best simulate/replace bool for a system that doesn't support C99/C++?

Richard

Originally Posted by Richardcavell

1. Do you consider bool to be a useful and necessary data type?

Useful, yes, necessary, no. When I'm working in a language that has them, I'll use the type. In C, I'll just use an int set to 0 or some other number. Some people use hungarian notation like "bVariableName" to indicate bools in C; your method has a little more polish.

Incidentally, even with respect to C99, an expression such as x > 10 results in an int (rather than _Bool, though it is possible that _Bool is int) that is either 0 or 1, so CommonTater's definition of Test could have been simplified to:

Code:

int Test(int x)
{
    return x > 10;
}

Not necessary in C perhaps, but it can certainly aid readability.
E.g. Say you found some code calling a homemade 'find' function. No code comments are present. Is it returning the index of the item found or is it returning one for found and zero for not found?

Originally Posted by CommonTater

That should be easily dscernable from the return statments... return A[index] is pretty much a give away.

Oh, I dunno. I reviewed some code a while back which did exactly that. The thing is, the caller had been required to ensure A[index] was either 0 or 1, and nothing else.

A willful programmer can make even simple things inscrutable.

In answer to the original question, bool is useful but not essential. In languages that don't have it, I don't attempt to emulate it.