On Thursday, 14 July 2016 at 09:12:50 UTC, Jonathan M Davis wrote:
So, whether you should be using Appender or assumeSafeAppend or
neither depends entirely on what you're doing. However, in
general, simply appending to dynamic arrays does not result in
many reallocations (just like it doesn't result in a lot of
realloctions for std::vector or ArrayList). When reallocations
become a problem is when you start slicing a dynamic array so
that you have other dynamic arrays which refer to the same
memory, and you append to those dynamic arrays, or when you
reduce the length of an array and then append to it, because in
both of those cases, you're appending to dynamic arrays which
do not refer to the last element in their underlying memory
block.
Hopefully, that makes things at least somewhat clearer.
- Jonathan M Davis
Thank you Jonathan, that really cleared up a lot of things, I
read the article. But I still have this doubt: is
assumeSafeAppend() changing a property of the array as "this
array is never going to be referenced by any other slice, you can
append or change its length any time and it is never going to be
reallocated unless it's out of free space"? or it is more like
"adjust capacity after last operation" so I should be calling it
whenever I am adjusting length or before appending?
