> For the complete documentation index, see [llms.txt](https://max-daunarovich.gitbook.io/flow-network/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://max-daunarovich.gitbook.io/flow-network/introduction/values-and-types/optionals/force-assignment-operator.md).

# Force-assignment operator

The force-assignment operator `<-!` assigns a resource-typed value to an optional-typed variable if the variable is nil. If the variable being assigned to is non-nil, the execution of the program aborts.

The force-assignment operator is only used for resource types and the move operator (`<-`), which are covered the resources section of this document.