diff options
Diffstat (limited to 'manual/=stddef.texi')
| -rw-r--r-- | manual/=stddef.texi | 18 |
1 files changed, 9 insertions, 9 deletions
diff --git a/manual/=stddef.texi b/manual/=stddef.texi index 28d4b26..e15fd73 100644 --- a/manual/=stddef.texi +++ b/manual/=stddef.texi @@ -9,7 +9,7 @@ definitions, your program should include the header file @pindex stddef.h @comment stddef.h -@comment ANSI +@comment ISO @deftp {Data Type} ptrdiff_t This is the signed integer type of the result of subtracting two pointers. For example, with the declaration @code{char *p1, *p2;}, the @@ -20,7 +20,7 @@ exists only for this purpose. @end deftp @comment stddef.h -@comment ANSI +@comment ISO @deftp {Data Type} size_t This is an unsigned integer type used to represent the sizes of objects. The result of the @code{sizeof} operator is of this type, and functions @@ -30,12 +30,12 @@ objects of arbitrary sizes accept arguments of this type to specify object sizes. @end deftp -In the GNU system @code{size_t} is equivalent to one of the types +In the GNU system @code{size_t} is equivalent to one of the types @code{unsigned int} and @code{unsigned long int}. These types have identical properties on the GNU system, and for most purposes, you -can use them interchangeably. However, they are distinct types, +can use them interchangeably. However, they are distinct types, and in certain contexts, you may not treat them as identical. For -example, when you specify the type of a function argument in a +example, when you specify the type of a function argument in a function prototype, it makes a difference which one you use. If the system header files declare @code{malloc} with an argument of type @code{size_t} and you declare @code{malloc} with an argument @@ -47,12 +47,12 @@ supposed to have type @code{size_t}, always write the type as actually be. @strong{Compatibility Note:} Types such as @code{size_t} are new -features of ANSI C. Older, pre-ANSI C implementations have +features of @w{ISO C}. Older, pre-ANSI C implementations have traditionally used @code{unsigned int} for representing object sizes and @code{int} for pointer subtraction results. @comment stddef.h -@comment ANSI +@comment ISO @deftypevr Macro {void *} NULL @cindex null pointer This is a null pointer constant. It can be assigned to any pointer @@ -60,7 +60,7 @@ variable since it has type @code{void *}, and is guaranteed not to point to any real object. This macro is the best way to get a null pointer value. You can also use @code{0} or @code{(void *)0} as a null pointer constant, but using @code{NULL} makes the purpose of the -constant more evident. +constant more evident. When passing a null pointer as an argument to a function for which there is no prototype declaration in scope, you should explicitly cast @@ -70,7 +70,7 @@ thing. @end deftypevr @comment stddef.h -@comment ANSI +@comment ISO @deftypefn {Macro} size_t offsetof (@var{type}, @var{member}) This expands to a integer constant expression that is the offset of the structure member named @var{member} in a @code{struct} of type |