Please support assignment operators within withexpressions.

[otac0n]

For example:

public record class State(double T, Camera Camera);

...

return state with
{
    T += elapsed.TotalSeconds,
    Camera ??= new(),
};

I tried to use this and found it missing.

I expect this to be similar to the following:

return state with
{
    T = state.T + elapsed.TotalSeconds,
    Camera = state.Camera ?? new(),
};

The difference I would expect is that the state expression would be evaluated only once with the former.

[333fred]

Duplicate of #5176.

[otac0n]

That should arguably be two issues. I don't think it makes as much sense in object initializers.