Can class fields be assigned in pattern assignments?

Trying to decompose a record to class fields gives the error "Only local variables can be assigned in pattern assignments". Is this unavoidable? Couldn't it be solved so that we can assign to class fields as well?

Start by reading the issue discussion and the Dart language specification to understand the current restriction on pattern assignments and class fields. Review the open design question and its trade-offs; done means the language-design decision is documented, with any required specification changes identified.

Written by the indexing model from the issue text.