Sorry: you seem to be misunderstanding me, but I do not know how to express myself better. Edit: for reference, I'm looking for an analog of the let! construct

Sorry: you seem to be misunderstanding me, but I do not know how to express myself better. Edit: for reference, I'm looking for an analog of the let! construct from "Linear types can change the world!" and the borrowing usage from the Linear Haskell paper.