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Help => General => Topic started by: EldarFara on April 18, 2020, 01:41:20 am

Title: (Solved) Read access violation with unknown reason
Post by: EldarFara on April 18, 2020, 01:41:20 am

Hello! I am getting read access violation while running game code, here is a minimal example:
https://pastebin.com/cEqKDaGk
It is designed to render some sprites to the RenderTexture and then render it to the window.
Exception occures on any line of Menu::DrawMenu().

(click to show/hide)

(https://cdn.discordapp.com/attachments/175298431294636032/700794917882167317/e5fe890470e00e20.png)
(https://cdn.discordapp.com/attachments/175298431294636032/700797181124149258/403e173ef04bcbea.png)

Code seems to work OK if I am not using vectors for storing Menu class.
C++ 17, SFML 2.5.1, VS 2019

Title: Re: Read access violation with unknown reason
Post by: Laurent on April 18, 2020, 09:52:23 am

Quote

Menus.push_back(&Menu());

You're storing the address of a temporary object. It is destroyed immediately so the address points to garbage after this line.

Title: Re: Read access violation with unknown reason
Post by: EldarFara on April 18, 2020, 12:33:36 pm

Thanks for your answer. I changed vector of object pointers to vector of objects (changed RenderTexture to RenderTexture* to make copy assignment possible) and now main() looks like this:

(click to show/hide)

int main()
{
   std::vector<Menu> Menus;
   Menus.push_back(Menu());
   Menus.back().DrawMenu();
   return 0;
}

This time, I get read access violation "this was 0x30" on the line with drawing to the window.

EDIT: I simplified code so much (to show a minimal example) that I deleted part with creating window, thats why I got read access violation. Problem is solved now. Cheers!