C#•2y ago

❔ Is there any way to create a pointer to a C# generic class

I have a script that uses a class "fogGrid<bool>". At the start of the script I want it to be able to specify which instance of the class is manipulated. Essentially I want fogGrid to be a pointer to instances of the same class in another script (SqrFog, TriFog or CirFog) I've allowed unsafe code to run, but whenever I try to run it, it states that "It cannot take the address of, get the size of, or declare a pointer to a managed type ("FogSystem<bool>") For tests sake i was just trying to get it to point to sqrFog. After some googling it says I cannot make pointers to generic types, is there any workaround?

18 Replies

Thinker•2y ago

What is sqrFog? Oh it's a FogSystem What is FogSystem? A class or a struct?

docklandslightrailwayOP•2y ago

For some clarification yeah I generate it from FogSystem in the game controller script

Thinker•2y ago

Is it a class or a struct?

docklandslightrailwayOP•2y ago

I think it'd be a structure?

docklandslightrailwayOP•2y ago

It just generates a grid to width by size and cellsize with each location storing a value of type TGridObject

Thinker•2y ago

You can't get a pointer to managed types, only to unmanaged structs

docklandslightrailwayOP•2y ago

Then it has a few methods around that to get and set

Thinker•2y ago

If FogSystem is a class then you don't need to use pointers and unsafe here in the first place If it's a struct then you can't force it to be the same instance because of how structs are stored

docklandslightrailwayOP•2y ago

What do you mean by this? the pointer isn't to the class but a specific instance of it stored in a different script. So I assumed it'd need the pointer to choose between instances

Thinker•2y ago

A class is a reference type, which means that doing a = b; sets a to the same instance as b.

docklandslightrailwayOP•2y ago

Oohhhh ok that makes so much sense

Thinker•2y ago

And you also can't get a pointer to a reference type. $refvsvalue

MODiX•2y ago

https://cdn.discordapp.com/attachments/364492811489509376/692833980650881084/pass-by-reference-vs-pass-by-value-animation.gif

docklandslightrailwayOP•2y ago

Thank you so much! Will have a play with that concept

MODiX•2y ago

thinker227#5176

REPL Result: Success

class C
{
    public int x;
}

C a = new();
a.x = 1;
C b = a;
b.x = 2;

Console.WriteLine(a.x);
Console.WriteLine(b.x);

class C
{
    public int x;
}

C a = new();
a.x = 1;
C b = a;
b.x = 2;

Console.WriteLine(a.x);
Console.WriteLine(b.x);

Console Output

2
2

2
2

Compile: 649.964ms | Execution: 32.327ms | React with ❌ to remove this embed.

docklandslightrailwayOP•2y ago

My code now works as intended and I can change the class that the script is referencing Learn something new everyday, thank you!

Thinker•2y ago

Accord•2y ago

Was this issue resolved? If so, run /close - otherwise I will mark this as stale and this post will be archived until there is new activity.

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❔ Is there any way to create a pointer to a C# generic class