with_rng_version() would be nice

[gaborcsardi]

To ease fixing the new RNG madness in 3.6.0.

[gaborcsardi]

I'll probably add an implementation to igraph tomorrow, because they make me fix this....

[gaborcsardi]

Here is what I wrote:

with_rng_version <- function(version, expr) {
  orig <- RNGkind()
  on.exit(do.call(RNGkind, as.list(orig)), add = TRUE)
  suppressWarnings(RNGversion(version))
  expr
}

local_rng_version <- function(version, .local_envir = parent.frame()) {
  orig <- RNGkind()
  defer(do.call(RNGkind, as.list(orig)), envir = .local_envir)
  suppressWarnings(RNGversion(version))
  orig
}

I can submit a PR if you want to have this in withr.

[jimhester]

A pr would be great!