out parameter with InterpolatedStringHandler

[FaustVX]

Hi,
I saw that gist some time ago a bout a C style of parsing string based on InterpolatedStringHandler,
And I tried to use out parameter instead of ref one, to have a nicer way of defining values.
But the compiler tells me that I try to use unassigned local values.

How can I tell the compiler that the out values (name and age) are fully assigned ?

// TryParse below use a custom Interpolated String Handler
if ("Name: FaustVX Age: 32".TryParse($"Name: {Get(out string? name)} Age: {Get(out int age)}"))
    Console.WriteLine($"{name}, {age}"); // <-- error CS0165: Use of unassigned local variable 'name' and 'age'

Here is a shortened version on sharplab.io

[333fred]

The problem with both the gist and this simpler example is that the compiler has no way to relate the bool returns of the handler to the result of TryParse. For all it knows, one of the AppendX methods could have failed, causing the subsequent ones to never be run. In order to get this (and the gist) to work, you'd have to make them return void, not bool, and have the handler just no-op for subsequent calls: https://sharplab.io/#v2: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=.

[FaustVX]

Ok, thanks,
I know the constructor of the Handler can have an out bool parameter, but it won't help for my situation.
It could be nice to have some kind of bool returning Closing method on the handler to validate if everything works well, but I don't know if it could be useful in other use cases.