C++ & Qt

21 May 2024 07:27

The point/rule is that auto can't deduce top-level const. i has a top-level const while none of s and pd has that.

C++ & Qt

19 May 2024 14:26

I think the newish Shapes module will do that.

C++ & Qt

19 May 2024 11:43

Oh, sorry, I have updated the link.

C++ & Qt

19 May 2024 11:42

So without canvas how can I draw an arc tho?

C++ & Qt

19 May 2024 11:30

Try not to use Canvas in QML if you care about your application's performance.
https://doc.qt.io/qt-6/qml-qtquick-shapes-conicalgradient.html

C++ & Qt

18 May 2024 20:33

What are you trying to do (that can’t be done)?

C++ & Qt

18 May 2024 16:19

Here is a html canvas version:

https://stackoverflow.com/questions/14193956/draw-arc-with-linear-gradient-in-html5-canvas

C++ & Qt

18 May 2024 16:12

I tried adding a gradient so that when the progress is at 0 it's black and when it reaches 100 its in cyan, I used linear gradient and it's not working as I intended it to

C++ & Qt

18 May 2024 14:14

a is S<const int> but not const S<const int>. It doesn't deduce anything there. The template was instantiated with const int, so it's const int.

q is const double * but not const double * const. It's a pointer to a constant object, but not a constant pointer.

C++ & Qt

18 May 2024 14:09

auto in a can deduce that the type is S<const int> not S<int>, likewise in q, it can deduce the type is const double* and not double*

C++ & Qt

18 May 2024 11:43

auto has been used for a and q with const deduced correctly without need to use const auto.

C++ & Qt

18 May 2024 11:25

I guess what Sébastien means is that you aren't wondering why

int i = 42;

C++ & Qt

18 May 2024 11:20

That’s like what has been written in the code above.

C++ & Qt

18 May 2024 11:16

int j = 42; // 42 is const (event constexpr) but j is not const

C++ & Qt

18 May 2024 11:09

template <typename T>
struct S {};

int main() {
S<const int> s;
s = S<const int>{}; // OK
auto a = s;// type of a is S<const int>

const int i{};
auto j = i; // type of j is int

const double *pd {new double(3.4)};
auto q = pd; // type of q
is const double*

// …
}

C++ & Qt

19 May 2024 14:30

https://doc.qt.io/qt-5/qml-qtquick-patharc.html

C++ & Qt

19 May 2024 11:45

You can use a combination of MultiEffect's opacity mask and ConicalGradient.
https://doc.qt.io/qt-6/qml-qtquick-shapes-conicalgradient.html

C++ & Qt

19 May 2024 11:42

Hi am new to qt i have some doubt how to use qface framework and how to create publisher / subscriber model is it really required IVI?

C++ & Qt

19 May 2024 11:40

Qt Graphical Effects is deprecated in Qt6 and available as part of QtCompat module. Alrenatives are Qt MultiEffects and Shapes.

C++ & Qt

18 May 2024 20:42

It's hard to explain but I'm just trying to mirror but the source is in a different window...actually different screen 😅

C++ & Qt

18 May 2024 20:28

Any chance there's a workaround for this error?
ShaderEffectSource: sourceItem and ShaderEffectSource must both be children of the same window
I already have a good plan and my code makes sense but this is a deal breaker and bug report said they won't fix it 😭

C++ & Qt

18 May 2024 16:13

This is what I'm trying to achieve

C++ & Qt

18 May 2024 16:11

Hey I was trying to implement a circular progress bar and tried something but it's not working as intended

C++ & Qt

18 May 2024 14:12

What you’ve mentioned are correct but yet there’s a little and subtle point remaining.

C++ & Qt

18 May 2024 11:53

a is not const and q neither. q can point to another double.

C++ & Qt

18 May 2024 11:26

If you need the same type on the left, use const auto explicitly or maybe decltype

C++ & Qt

18 May 2024 11:22

I did not understand the question then

C++ & Qt

18 May 2024 11:18

auto j = i; // j is not const, even when i is const

C++ & Qt

18 May 2024 11:10

Kind of a challenge.

Why does auto behave differently in deducing const for j?

C++ & Qt

17 May 2024 20:33

Hi, I need someone who can make a Tetris application in Qt