Round to multiple of integer

I frequently find it useful to round to multiple of an integer, most commnly 5, powers of 10, and similar.

First, I usually use something like

round_to(n, x) = round(Int, x / n) * n

Is there a better implementation? Just being curious, this is not performance-critical.

Second, is there a package with this kind of functionality? If not, would it make sense to add to some existing package?

If you want to round up/down to powers of something, I’d use nextpow and prevpow respectively, see

help?> nextpow
search: nextpow nextprod

  nextpow(a, x)

  The smallest a^n not less than x, where n is a non-negative integer. a must
  be greater than 1, and x must be greater than 0.

For a rounding to the nearest such power, a simple branch or if-else should work too.

There’s also nextprod and prevprod (mentioned in the docstring above) which might be useful in certain situations but generally I think your function should work well enough.