Undocumented aspect of result builder

Using Swift
1

TLDR: result builders' buildExpression supports @autoclosure:

@MainActor
@resultBuilder
struct BodyBuilder {
    
    static var shouldExecuteExpressions = false

    static func buildExpression<T>(_ expression: @autoclosure () -> T) {
        if Self.shouldExecuteExpressions {
            _ = expression()
        }
    }
    
    static func buildBlock(_: Void...) { }
    
}

This is handy for some code that I'm writing, but it isn't explicitly documented anywhere (though the fact that it works makes sense to me.)

Is it reliable to depend on this, and if so, is it worth documenting?

1 Like
2

The closest I can find of "documented" is in the Future Directions that references usage of a valid @autoclosure to justify other developments.

1 Like
3

Yeah I saw that too :thinking: The "future" part is why I was surprised it worked