core: don't copy App and apprt.App

[jcollie]

Besides avoiding copying, this allows consumers to choose to allocate these structs on the stack or to allocate on the heap. It also gives the apprt.App a stable pointer sooner in the process.

[mitchellh]

I'm not against it but again... why now? Is this change for change sake or is there a motivating thing you're working on?

[jcollie]

I'm not against it but again... why now? Is this change for change sake or is there a motivating thing you're working on?

Yeah, as I was working on some of the changes needed to get the GTK apprt structs to use DerivedConfigs instead of using the "raw" config this made some things easier. Plus it's more consistent with how the other GTK structs are handled (Window, Tab, Surface).

[gabydd]

Just a little thing. Also i agree having app be a stable pointer would have been useful for me at some point(though it's also not that bad to have to allocate a couple objects for callbacks) but is there a reason that CoreApp needs a stable pointer?

[jcollie]

is there a reason that CoreApp needs a stable pointer

I don't have a particular use case or need at this time but made the change now for consistency's sake.

[gabydd]

Sorry about the churn on this part

[gabydd]

This part of the error defer has to be above the init so if the init fails then it will be destroyed. The ordering will still be correct as the second errdefer runs first see this as an example

const std = @import("std");

fn fail() !void {
    return error.Fail;
}
pub fn main() !void {
    errdefer std.debug.print("prints second\n", .{});
    errdefer std.debug.print("prints first\n", .{});
    try fail();
}