How to convert from Large RasterLayer to Formal RasterLayer class in R?

Question

I'm a bit confused about types here. While I'm loading a image:

tif = raster(paste0(path))

I get some "Formal Class RasterLayer" object. But while I change it's matrix of values, for example:

idx <- values(tif) != 200
  values(tif)[idx] <- 255

if becomes "Large RasterLayer" object. And indeed it's large, for file of about 100Mpx it's over 270mb, while that first is about 10mb in memory.

How can I convert this new one into the "Formal" class to save memory?

I tried: tif1 = raster(tif) but object missing coordinates. as.raster(tif) returns raster chr variable.

EDIT

Found a workaround:

writeRaster(tif, "tif.tif")
tif = raster("tif.tif")

It takes much memory for process but at last its freed. Wish to find something faster without saving to disk.