Re: macro for fir list?

Opus wrote:

On 28/03/2024 14:40, fir wrote:

>
you know famous fir list
>
fir list its a list container i somewhat "invented",
i write "invented" as its reasonably simple thing but i never heard
anyone uses it so as for me i invented it for personal use and use it

>
It's a pretty common thing though. It's just that it's not standard, so
everyone does it pretty much in their own way.
>
In my way, I avoid to realloc the 'dynamic array' everytime a new item
is appended, as it can be a costly operation. I pre-allocate for a
certain number of items, and keep track of the current number of items
and the current size of the 'dynamic array'. If there is enough room
left, I just add the item, no realloc needed. If there isn't, then I
realloc, with not just room for 1 item, but a whole new block, for the
same reason. You get the idea.
>
This is a common way of dealing with such dynamic containers. (See: bump
allocators, and all that...)
>

some could usually wrote a more convenient Add "method" not to pass
structures but just arguments and struct assigment do inside

>
 From what I get - it's not fully clear - you'd like to directly pass a
structure 'literal' to your function, rather than having to go via an
intermediate local variable.
>
This is exactly what C99 has brought, among other things, for over 20
years. Do not hesitate to use it: compound literals.
>
For instance with your code, you can do this instead:
>
Fir_List_AddOne(&(struct Fir_List_Entry){ 11, 22 });
>
Yes, the 'cast' in front of the braces is mandatory for compound literals.
>
Note that your posted code is incorrect, you need to either refer to
'Fir_List_Entry' with 'struct Fir_List_Entry', or typedef it prior.
I think omitting the 'struct' is allowed in C++, not so in C.
>
Conversely, I'm not sure compound literals (which I find very handy) are
available in C++. But if you were using C++, you wouldn't need to do the
above anyway, so. Just mentioning it.
>

i think teh idea is rather not obvius, i agree people use dynamic alocation, more rarely they use reallock atc but the pure idea
of list like here is imo not much in use imo... - if that would be in
use it would be generally used as this is some kind of composition
pattern and that would substitule ways people usually du such things
in c largely...as to the line you say i may test it
i coode in c++ mode and in c mode tu though in c++ more often
checked seem not to work: error: taking adress of temporary
as this list idea people may obviously take it uuse it and then say, oh,
i was using it - but in facy as i know how c people code (right from this group etc) they dont use it, unless thay maybe begin using it in last few years
when i started using it (see my more historic post about 'chunks' and 'splitter') i used the appproach with variable holding the preallocated value... then i dropped it becouse reallock already stores such number under the hood so this is kinde reapeating the same thing - but then later it showed that stiill doubling it may speed things becouse
(as far as i remember becouse i dont remember exact values ) this
call to reallock even if this do almosc nothing still may cost if this is in more time critical case