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diff --git a/manual/=stddef.texi b/manual/=stddef.texi deleted file mode 100644 index e15fd7375f..0000000000 --- a/manual/=stddef.texi +++ /dev/null @@ -1,81 +0,0 @@ -@node Common Definitions, Memory Allocation, Error Reporting, Top -@chapter Common Definitions - -There are some miscellaneous data types and macros that are not part of -the C language kernel but are nonetheless almost universally used, such -as the macro @code{NULL}. In order to use these type and macro -definitions, your program should include the header file -@file{stddef.h}. -@pindex stddef.h - -@comment stddef.h -@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 -expression @code{p2 - p1} is of type @code{ptrdiff_t}. This will -probably be one of the standard signed integer types (@code{short int}, -@code{int} or @code{long int}), but might be a nonstandard type that -exists only for this purpose. -@end deftp - -@comment stddef.h -@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 -such as @code{malloc} (@pxref{Unconstrained Allocation}) and -@code{memcpy} (@pxref{Copying and Concatenation}) that manipulate -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 -@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, -and in certain contexts, you may not treat them as identical. For -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 -of type @code{unsigned int}, you will get a compilation error if -@code{size_t} happens to be @code{unsigned long int} on your system. -To avoid any possibility of error, when a function argument is -supposed to have type @code{size_t}, always write the type as -@code{size_t}, and make no assumptions about what that type might -actually be. - -@strong{Compatibility Note:} Types such as @code{size_t} are new -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 ISO -@deftypevr Macro {void *} NULL -@cindex null pointer -This is a null pointer constant. It can be assigned to any pointer -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. - -When passing a null pointer as an argument to a function for which there -is no prototype declaration in scope, you should explicitly cast -@code{NULL} or @code{0} into a pointer of the appropriate type. Again, -this is because the default argument promotions may not do the right -thing. -@end deftypevr - -@comment stddef.h -@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 -@var{type}. For example, @code{offsetof (struct s, elem)} is the -offset, in bytes, of the member @code{elem} in a @code{struct s}. This -macro won't work if @var{member} is a bit field; you get an error from -the C compiler in that case. -@end deftypefn |