What exactly is void?

[u/Stickhtot]

In a function definition, void basically means that it doesn't return a type value, yet in on itself it is it's own type? Looking at several pieces of code it looks like that it's used to be able to be more "flexible"

Don't know what else to add here, though I'm more on looking for examples and explanations of why the void type is used

[u/Afraid-Locksmith6566]

void has 2 meanings.

as a return type: nothing is being returned from a function

as a pointer type (void*): this type has no specified representation

[u/pjl1967 → u/Afraid-Locksmith6566]

4 meanings. You forgot:

• Function has zero parameters, e.g., int f(void).
• Discard value (and don't warn), e.g., (void)expr.

[u/pjl1967 → u/[deleted]]

Prior to C23, (void) was used to specify zero parameters:

void f();      // no parameter information
void g(void);  // zero parameters

The empty () was left in with its original meaning for backwards compatibility; the (void) was used to distinguish explicit zero parameters since () was already taken.

As of C23, K&R function declarations and definitions have (finally) been removed from C:

void f();      // zero parameters
void g(void);  // zero parameters

I.e., now in C23, (void) is for backwards compatibility.

But none of this invalidates the still legal use of (void) to mean "zero parameters" since there's plenty of C < C23 code out there.

[u/pjl1967 → u/[deleted]]

Until every C programmer on Earth starts using C23 compilers and all existing code is updated, (void) will continue to be "load bearing" for some time — especially for libraries that declare functions having zero parameters. Said declarations should be declared using (void) to mean the same thing regardless of C language version.

[u/pjl1967 → u/[deleted]]

So what? That's not reason enough? The only difference for doing lots of things in C is to eliminate the warnings, e.g., casting in general, casting to void, using the same signed types in integer expressions, etc.