15-Nov-2014 01:38, Steven Schveighoffer пишет:
On 11/14/14 5:25 PM, Dmitry Olshansky wrote:
15-Nov-2014 01:16, IgorStepanov пишет:
Recently I encountered the following problem.
I need a simple stack of uint.
I want to push uints back and pop it. I don't want to copy this stack
and I want it to work fast.
In a first approximation, the problem seems easy.
uint[] my_stack;
my_stack.reserve(256);
my_stack ~= 1; //push
uint head = my_stack[$ - 1]; //top
my_stack.length--; //pop
Just make push into:
my_stack.assumeSafeAppend();
my_stack ~= value;
To avoid relocations.
In actuality, you do not need this before every push. You only need it
between a pop and a push.
I highly recommend not doing arrays-as-stacks, because you end up
writing your own type.
+1
At that point, you may as well remove the funky
array/slice semantics, and store the capacity yourself.
That's the second approximation ;)
The third goes to C's malloc.
The 4-th starts with some small array on stack, then goes to C's malloc.
--
Dmitry Olshansky
