Polymorphism and std::vector

Asked Nov 01 '14 at 03:37

Active Nov 01 '14 at 03:47

Viewed 121 times

So I have a vector of "Widgets"

std::vector<Widget> widgets;

And a class called dial which extends Widget

class Dial : public Widget

And also a loop which loops through all the Widgets in widgets. However, there is and update method in Widget which gets overriden in Dial, and whenever I loop through widgets it calls Widget's update and not Dial's update. How can I fix this? (It also calls Widget's draw and not Dial's as well)

edited Nov 01 '14 at 03:47

asked Nov 01 '14 at 03:37

Asad-ullah Khan

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This has nothing to do with vectors. – chris Nov 01 '14 at 03:37
@chris How so? I AM using vectors – Asad-ullah Khan Nov 01 '14 at 03:41
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You are the victim of *slicing*. To fix it you must use a vector of `Widget*` and not `Widget`. – Mark Ransom Nov 01 '14 at 03:46
@jogojapan I am trying that but it says std has no member unique_ptr – Asad-ullah Khan Nov 01 '14 at 03:46
@MarkRansom Alright, what can i do to fix it – Asad-ullah Khan Nov 01 '14 at 03:46
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@KhanPower You need C++11 for `unique_ptr`. Depending on the compiler you are using, the `-std=c++11` command line option might get you there. – jogojapan Nov 01 '14 at 03:48

Polymorphism and std::vector

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