dynamic array memory allocation

Derek Parnell derek at psych.ward
Wed May 16 03:46:52 PDT 2007


On Wed, 16 May 2007 02:30:35 -0400, Greg Weber wrote:

> I find myself wondering what actually happens when I create a dynamic array and concatenate items onto it.  I think I read in a post that memory will be over-allocated at times to avoid re-allocating.
> 
> I think it would help out a lot to have an ability to specify over-allocation.  Something like
> uint a = [];
> a.length = 3:10
> 
> Where the array length is 3, but you are guaranteed to have memory allocation for 10, so you can be guaranteed that concatenation up to ten will not need to allocate memory.  This could help in the situation where there is concatenation in a loop, and the programmer over-sizes the array before the loop and re-sizes after the loop.

In those situations I do this ...

  uint[] a;
  a.length = 10;
  a.length = 3;

This keeps the 10 (actually 16 I think) allocated while setting the length
to 3.

-- 
Derek Parnell
Melbourne, Australia
"Justice for David Hicks!"
skype: derek.j.parnell



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