Hello, I have a C function in which I want to return a result visibly or invisibly (depends on the arguments provided). My current implementation was to return a list like 'withVisible' does, where element "value" is the value the function returns, and element "visible" is TRUE or FALSE depending on whether the result is returned visibly or not. Something like: { value <- .External(C_fun, ...) if (value$visible) value$value else invisible(value$value) } Is there a way to do this in C instead? Thank you! [[alternative HTML version deleted]]