when to use uint? dis/advantages?

[Song Yun Zhao]

Hi,

Just wondering what are the dis/advantages of using uint vs int. When
would be the best time to use it?

Personally I don't use uint that much, but I like to optimize my code
and make it as effective as possible. So I feel that using an int where
only an uint is needed is a waste.

e.g. something like (int i = 0; i < 100; i++)
could probably better be written as (uint i = 0; i < 100; i++)
or maybe even better (unsigned short i = 0; i < 100; i++)

One big advantage of using uint is that if I have a function like

void foobar(uint i)
{
if (i >= 0) {
cout << "generate a warning, this is always true" << endl;
}
}

and calling foobar(-1) will generate a warning. This can help me iron
out some problems/bugs at compile time.

However using uint does require more work, for example when comparing an
uint to int will generate a warning, hence would require a static_cast.

Anyway, I want to know what other programmers are doing. I use Qt a lot
at work, and I don't see a lot of uint in Qt's code. Could this be for
portability reasons?

Anyway all comments are appricated. TIA.

Song

[Jonathan Turkanis]

Song Yun Zhao wrote:

Hi,

Just wondering what are the dis/advantages of using uint vs int.

What's uint?

Jonathan

[Song Yun Zhao]

Jonathan Turkanis wrote:

What's uint?

Jonathan

unsigned int

[Jonathan Turkanis]

Song Yun Zhao wrote:

Jonathan Turkanis wrote:

What's uint?

unsigned int

Or it could be:

typedef mounatin_range< uinta> uint;

Jonathan

[Song Yun Zhao]

Jonathan Turkanis wrote:

Or it could be:

typedef mounatin_range< uinta> uint;

Jonathan

what's ur point?

[Jonathan Turkanis]

Song Yun Zhao wrote:

Jonathan Turkanis wrote:

Or it could be:

typedef mounatin_range< uinta> uint;

Jonathan

what's ur point?

I meant to say mountain_range. Now is everything clear?

Jonathan

[rajkumar]

Hey

Lots of functions return 0 - N for okay and -1 for error conditions.
If you store these values in a unsigned int you will never be able to
detect these error conditions.

Also if somebody refactors you code later and changes

for ( unsigned int i = 0; u < 100 ; i++ )

to

for ( unsigned int i = 100 -1 ; i >= 0 ; --i )

you get an infinite loop
Raj

[Song Yun Zhao]

Jonathan Turkanis wrote:

I meant to say mountain_range. Now is everything clear?

not really, r u trying to say that uint is not a standard type?

Song

[Ioannis Vranos]

Song Yun Zhao wrote:

Hi,

Just wondering what are the dis/advantages of using uint vs int. When
would be the best time to use it?

In technical discussions we strive for accuracy. uint does not mean
anything in particular.

Personally I don't use uint that much, but I like to optimize my code
and make it as effective as possible. So I feel that using an int where
only an uint is needed is a waste.

e.g. something like (int i = 0; i < 100; i++)
could probably better be written as (uint i = 0; i < 100; i++)
or maybe even better (unsigned short i = 0; i < 100; i++)

One big advantage of using uint is that if I have a function like

void foobar(uint i)
{
if (i >= 0) {
cout << "generate a warning, this is always true" << endl;
}
}

and calling foobar(-1) will generate a warning. This can help me iron
out some problems/bugs at compile time.

assigning -1 to an unsigned integral type variable, assigns the maximum
value of its type to it.
However using uint does require more work, for example when comparing an
uint to int will generate a warning, hence would require a static_cast.

Anyway, I want to know what other programmers are doing. I use Qt a lot
at work, and I don't see a lot of uint in Qt's code. Could this be for
portability reasons?

Anyway all comments are appricated. TIA.

Use signed integral types when you need to use them for negative values
too. If you deal only with positive values and/or want to have more
positive value range at the same type size, use the unsigned types.

--
Ioannis Vranos

http://www23.brinkster.com/noicys

[shabbir]

uint and int will not make a slight of difference in todays speed of
computer and its almost obsolete.

it is there in C++ for a simple reason "Backward compatibility" and
will not make any help to you as far as my shallow knowledge goes.