Is there any method of referencing each of the controls on a form?

JonB

@Chris-Kawa
You're right. I'm too lazy to write the necessary for a recursive children() example (I don't even do C++ these days!), so we'll leave that as an exercise for the potential interested reader ;)

Chris Kawa

I'm too lazy to write the necessary for a recursive children() example

<tin foil hat on> Admit it. You're just an alien lizard in disguise trying to drain our batteries so we can't look at cat videos on a long distance bus trips :)

JonB

@Chris-Kawa

<tin foil hat on> Admit it. You're just an alien lizard in disguise trying to drain our batteries so we can't look at cat videos on a long distance bus trips :)

Whatever that is reference to I'm afraid it's completely beyond me? :(

JKSH

@JonB said in Is there any method of referencing each of the controls on a form?:

@Chris-Kawa

<tin foil hat on> Admit it. You're just an alien lizard in disguise trying to drain our batteries so we can't look at cat videos on a long distance bus trips :)

Whatever that is reference to I'm afraid it's completely beyond me? :(

Tin foil hat - The armour of choice for conspiracy theorists.
Alien (from outer space) - A common subject among conspiracy theorists.
Drain batteries - A consequence of a smartphone running inefficient code. Interferes with the smartphone's ability to play cat videos.
Cat videos - One of the top productivity killers in today's society. Often consumed via smartphones.
Long distance bus trips - A death trap for batteries that power smartphones that play cat videos. Can be counteracted by uber-modern busses that contain built-in phone chargers.

JonB

@JKSH
Errr, OK, but are you saying using a C-style cast will run out batteries?? ;-)

Chris Kawa

@JonB said in:

but are you saying using a C-style cast will run out batteries?? ;-)

Well, to play devil's advocate - kinda yes. A C-style cast in C++ is not the same as a cast in C. The compiler does some logic to determine which type of C++ cast to do underneath, so while the end result in the binary is the same the explicit C++ cast is cheaper in terms of compilation overhead (whatever microscopic amount that is). So if you're compiling on a battery powered laptop - yes, technically C-style casts in C++ will drain your battery more :D

JonB

@Chris-Kawa
To play devil's advocate back: please give me any (correct) example of where a C-style cast (compared to, say, static_cast<>()) could lead to battery-drain? Any example would do, I'm truly interested. Assuming you don't mean: a completely incorrect C-cast (like (int)some_struct or anything like that). Because I can't think of one....

Chris Kawa

@JonB It was a joke. We might end it here :) But I'll play along:

int a = 42;

float expensive  = (int)a;
float cheap = static_cast<int>(a);

The resulting binary and thus runtime performance are exactly the same. I meant compiler performance. (int)a makes the compiler check stuff to see which cast - const, static, reinterpret or some combination it needs to apply. Explicit C++ cast skips those checks so it's faster to compile. Again - It's not a difference that matters at all. It's extremely small so treat what I said as an (failed I admit) attempt at being funny. I bet glowing one pixel on your screen for a second takes more power than all the casts in your app.

JonB

@Chris-Kawa
Oh, you mean compile-time battery power? I thought you meant run-time.

(int)a makes the compiler check stuff to see which cast - const, static, reinterpret or some combination it needs to apply.

I could be wrong, but I think C-cast like (int)a always maps to static_cast<>(a), not the others.

Explicit C++ cast skips those checks so it's faster to compile

I'll make a little bet with you. Compiling a C-style cast in a C compiler will be faster than a static_cast<> in a C++ compiler. Not that I'm saying you were comparing against a C-only compiler. Based on nothing other than my suspicions :) But your point taken.

Chris Kawa

I'll make a little bet with you. Compiling a C-style cast in a C compiler will be faster than a static_cast<> in a C++ compiler.

I won't take that bet because I agree with you :) C is a lot simpler language to parse in general. Thinking about overload resolution alone leaves me no doubts that compiling the same code in C will always be faster than in C++. Again - talking about compile time performance, not runtime.

I could be wrong, but I think C-cast like (int)a always maps to static_cast<>(a), not the others.

It does in this case, but it needs to do the checklist anyway: explicit cast.
In case of something else, like const int foo = (const int)bar it will map to const_cast<const int>(bar).
I'm saying it's the logic to figure out which cast to use is the slow part.