Re: how cast works?

Thiago Adams <thiago.adams@gmail.com> writes:

On 07/08/2024 17:08, Keith Thompson wrote:

Thiago Adams <thiago.adams@gmail.com> writes:

How cast works?
Does it changes the memory?
For instance, from "unsigned int" to "signed char".
Is it just like discarding bytes or something else?

>
I also curious about how bool works.
>
Values converted to bool became 0 or 1.
When this conversion happens, at read or write? Both?

I don't know what you mean by that.

A conversion takes a value of some type and yields a value of some
(other) type.  If the target type is bool, the result is false (0) if
the operand is equal to zero, true (1) otherwise.

A cast is simply an explicit conversion.  Explict and implicit
conversions do the same thing.  (Some conversions can only be done
explicitly.)

A converted value does not "become" 0 or 1; the conversion *yields*
0 or 1.  The value of (bool)42 is 1, but 42 is still 42.

How much does it cost?

It depends on what code the compiler generates; the language doesn't
address that.  It could be free if the result isn't used and the
compiler optimizes it away.

[...]

--
Keith Thompson (The_Other_Keith) Keith.S.Thompson+u@gmail.com
void Void(void) { Void(); } /* The recursive call of the void */