[R] Scoped options setting?

[Zack Weinberg]

Is there any way to set options during the evaluation of a particular
expression, with them automatically reset when control leaves that
expression, however that happens?  Kind of like "let" on a "special"
variable does in Lisp.  I naively tried

with(options(warn=-1), {
    fit <- fitdistr(data, 'weibull')  # complains about NaNs
})

but this leaves options('warn') set to -1 afterward.  I can save and
restore the value explicitly, but then if fitdistr() throws an error,
it won't get reset...

zw