C++ container question

I want to store objects into a C++ container (e.g. vector<object>,
deque<object>). Could someone help me the following questions.

1. Does there exist any size limit in the C++ container. For example, how
many objects can be stored in the vector<object>?

2. I want to store many thousand objects into a container, and use "find",
"sort" very often. Which standard container should be used in term of
efficiency and size limit?

Thanks.

Pat

re: C++ container question

"Pat" <Pat@Pat.com> wrote in message news:4083ffbd$1_3@rain.i-cable.com...[color=blue]
> I want to store objects into a C++ container (e.g. vector<object>,
> deque<object>). Could someone help me the following questions.
>
> 1. Does there exist any size limit in the C++ container. For example, how
> many objects can be stored in the vector<object>?
>
> 2. I want to store many thousand objects into a container, and use "find",
> "sort" very often. Which standard container should be used in term of
> efficiency and size limit?
>
> Thanks.
>
> Pat
>
>[/color]
1. Yes, no computer has infinite memory. It will be the lesser of the
value returned by vector::max_size() or what can fit in available memory.

2. From your description, it sounds as if std::set<> or std::map<> would be
best. They will stay sorted automatically and your finds will be
efficient - logarithmic time.

re: C++ container question

Thanks Dave.

"Dave" <better_cs_now@yahoo.com> ¦b¶l¥ó
news:10880hssq806r3b@news.supernews.com ¤¤¼¶¼g...[color=blue]
>
> "Pat" <Pat@Pat.com> wrote in message news:4083ffbd$1_3@rain.i-cable.com...[color=green]
> > I want to store objects into a C++ container (e.g. vector<object>,
> > deque<object>). Could someone help me the following questions.
> >
> > 1. Does there exist any size limit in the C++ container. For example,[/color][/color]
how[color=blue][color=green]
> > many objects can be stored in the vector<object>?
> >
> > 2. I want to store many thousand objects into a container, and use[/color][/color]
"find",[color=blue][color=green]
> > "sort" very often. Which standard container should be used in term of
> > efficiency and size limit?
> >
> > Thanks.
> >
> > Pat
> >
> >[/color]
> 1. Yes, no computer has infinite memory. It will be the lesser of the
> value returned by vector::max_size() or what can fit in available memory.
>
> 2. From your description, it sounds as if std::set<> or std::map<> would[/color]
be[color=blue]
> best. They will stay sorted automatically and your finds will be
> efficient - logarithmic time.
>
>[/color]

re: C++ container question

|
| "Pat" <Pat@Pat.com> wrote in message news:4083ffbd$1_3@rain.i-cable.com...
| > I want to store objects into a C++ container (e.g. vector<object>,
| > deque<object>). Could someone help me the following questions.

| > 2. I want to store many thousand objects into a container, and use
"find",
| > "sort" very often. Which standard container should be used in term of
| > efficiency and size limit?

| 2. From your description, it sounds as if std::set<> or std::map<> would
be
| best. They will stay sorted automatically and your finds will be
| efficient - logarithmic time.

Depending on the object size, do consider
vector<Object> + sort() + binary_search()
for smaller objects.

br

Thorsten

re: C++ container question

"Thorsten Ottosen" <nesotto@cs.auc.dk> wrote in message
news:40847e80$0$25655
[color=blue]
> Depending on the object size, do consider
> vector<Object> + sort() + binary_search()
> for smaller objects.[/color]

For large objects, vector<smart_ptr<Object>> could work too. (Of course,
this is same as vector<T> with T very small).

re: C++ container question

"Siemel Naran" <SiemelNaran@REMOVE.att.net> wrote in message
news:z_0hc.1555$_o3.43361@bgtnsc05-news.ops.worldnet.att.net...
| "Thorsten Ottosen" <nesotto@cs.auc.dk> wrote in message
| news:40847e80$0$25655
|
| > Depending on the object size, do consider
| > vector<Object> + sort() + binary_search()
| > for smaller objects.
|
| For large objects, vector<smart_ptr<Object>> could work too. (Of course,
| this is same as vector<T> with T very small).

not quite since there is an additional overhead by the smart pointers
control block and the indirection. If searching is
done many times and sorting is done eg 1 time, vector<object> will
outperform vector<smart_ptr<object> >.

br

Thorsten

re: C++ container question

Thanks Thorsten.

Is it possible to increase the "max_size"?

Pat

"Thorsten Ottosen" <nesotto@cs.auc.dk> ¦b¶l¥ó
news:40847e80$0$25655$afc38c87@news.optusnet.com.a u ¤¤¼¶¼g...[color=blue]
> |
> | "Pat" <Pat@Pat.com> wrote in message[/color]
news:4083ffbd$1_3@rain.i-cable.com...[color=blue]
> | > I want to store objects into a C++ container (e.g. vector<object>,
> | > deque<object>). Could someone help me the following questions.
>
> | > 2. I want to store many thousand objects into a container, and use
> "find",
> | > "sort" very often. Which standard container should be used in term of
> | > efficiency and size limit?
>
> | 2. From your description, it sounds as if std::set<> or std::map<>[/color]
would[color=blue]
> be
> | best. They will stay sorted automatically and your finds will be
> | efficient - logarithmic time.
>
> Depending on the object size, do consider
> vector<Object> + sort() + binary_search()
> for smaller objects.
>
> br
>
> Thorsten
>
>[/color]

re: C++ container question

"Pat" <Pat@Pat.com> wrote in message news:<408492e2$1_2@rain.i-cable.com>...[color=blue]
> Thanks Thorsten.
>
> Is it possible to increase the "max_size"?
>
> Pat[/color]

Usually, the maximum size of a vector is determined at runtime by the
available memory. and/or the number of bits in a pointer. Technically
it is controlled by something called an allocator, which can be replaced.
In practice, I don't know any implementation where max_size is easily
increased. The allocators AFAIK are limited by OS and CPU constraints.
I.e. they're good enough for the amount of memory present.

Regards,
Michiel Salters