Thanks, Jacob and Stefan. What happens if you overestimate? Is the allocated-but-not-used memory eventually freed, or is it tied up until the object gets removed?
On Wednesday, October 21, 2015 at 12:18:28 PM UTC-7, Stefan Karpinski wrote: > > If you expect that you're going to have to push a lot of values onto a > vector, you can avoid the cost of incremental reallocation by doing it once > up front. > > On Wednesday, October 21, 2015, Jacob Quinn <quinn....@gmail.com > <javascript:>> wrote: > >> The way I came to understand was to just take a peak at the [source code]( >> https://github.com/JuliaLang/julia/blob/ae154d076a6ae75bfdb9a0a377a6a5f9b0e1096f/src/array.c#L670); >> >> I find it pretty legible. The basic idea is that the underlying "storage" >> of a Julia Array{T,N} can actually be (and often is) different than the >> size(A) in Julia. sizehint! modifies that underlying storage without >> changing the size(A) in Julia. >> >> -Jacob >> >> On Wed, Oct 21, 2015 at 12:46 PM, Seth <c...@bromberger.com> wrote: >> >>> I know it's good to use sizehint! with an estimate of the sizes of >>> (variable-length) containers such as vectors, but I have a couple of >>> questions I'm hoping someone could answer: >>> >>> 1) what are the benefits of using sizehint!? (How does it work, and >>> under what circumstances is it beneficial?) >>> 2) what are the implications (positive/negative, if any) of >>> overestimating the size of a container? >>> >>> Thanks. >>> >> >>
