Difference between uint and unsigned int?
CGccUintC Problem Overview
Is there any difference between uint and unsigned int?
I'm looking in this site, but all questions refer to C# or C++. I'd like an answer about the C language.
If it is relevant, note that I'm using GCC under Linux.
C Solutions
Solution 1 - C
uint isn't a standard type - unsigned int is.
Solution 2 - C
Some systems may define uint as a typedef.
typedef unsigned int uint;
For these systems they are same. But uint is not a standard type, so every system may not support it and thus it is not portable.
Solution 3 - C
I am extending a bit answers by Erik, Teoman Soygul and taskinoor
uint is not a standard.
Hence using your own shorthand like this is discouraged:
typedef unsigned int uint;
If you look for platform specificity instead (e.g. you need to specify the number of bits your int occupy), including stdint.h:
#include <stdint.h>
will expose the following standard categories of integers:
-
Integer types having certain exact widths
-
Integer types having at least certain specified widths
-
Fastest integer types having at least certain specified widths
-
Integer types wide enough to hold pointers to objects
-
Integer types having greatest width
For instance,
> Exact-width integer types > > The typedef name int N _t designates a signed integer type with width > N, no padding bits, and a two's-complement representation. Thus, > int8_t denotes a signed integer type with a width of exactly 8 bits. > > The typedef name uint N _t designates an unsigned integer type with > width N. Thus, uint24_t denotes an unsigned integer type with a width > of exactly 24 bits.
defines
int8_t
int16_t
int32_t
uint8_t
uint16_t
uint32_t
Solution 4 - C
All of the answers here fail to mention the real reason for uint.
It's obviously a typedef of unsigned int, but that doesn't explain its usefulness.
The real question is,
> Why would someone want to typedef a fundamental type to an abbreviated > version?
To save on typing?
No, they did it out of necessity.
Consider the C language; a language that does not have templates.
How would you go about stamping out your own vector that can hold any type?
You could do something with void pointers,
but a closer emulation of templates would have you resorting to macros.
So you would define your template vector:
#define define_vector(type) \
typedef struct vector_##type { \
impl \
};
Declare your types:
define_vector(int)
define_vector(float)
define_vector(unsigned int)
And upon generation, realize that the types ought to be a single token:
typedef struct vector_int { impl };
typedef struct vector_float { impl };
typedef struct vector_unsigned int { impl };
Solution 5 - C
The unsigned int is a built in (standard) type so if you want your project to be cross-platform, always use unsigned int as it is guarantied to be supported by all compilers (hence being the standard).
Solution 6 - C
The uint is a possible and proper abbreviation for unsigned int. It is better readable. But: It is not C standard. You can define and use it (as all other defines) to your own responsibiity.
But unfortunately some system headers define uint too. I have found in a sys/types.h from a currently compiler (ARM):
# ifndef _POSIX_SOURCE
//....
typedef unsigned short ushort; /* System V compatibility */
typedef unsigned int uint; /* System V compatibility */
typedef unsigned long ulong; /* System V compatibility */
# endif /*!_POSIX_SOURCE */
It seems to be a concession for familiary sources programmed as Unix System V standard. To switch off this undesired behaviour (because I want to
#define uint unsigned int
by myself, I have set firstly
#define _POSIX_SOURCE
A system's header must not define things which is not standard. But there are many things which are defined there, unfortunately.
See also on my web page https://www.vishia.org/emc/html/Base/int_pack_endian.html#truean-uint-problem-admissibleness-of-system-definitions resp. https://www.vishia.org/emc.