c99

As I understand it, the C specification says that type int is supposed to be the most efficient type on target platform that contains at least 16 bits. Isn't that exactly what the C99 definition of int_fast16_t is too? Maybe they put it in there just for consistency, since the other int_fastXX_t are needed? Update To summarize discussion below: My question was wrong in many ways. The C standard does not specify bitness for int . It gives a range [-32767,32767] that it must contain. I realize at first most people would say, "but that range implies at least 16-bits!" But C doesn't require two's

Is the difference of two non-void pointer variables defined (per C99 and/or C++98) if they are both NULL valued? For instance, say I have a buffer structure that looks like this: struct buf { char *buf; char *pwrite; char *pread; } ex; Say, ex.buf points to an array or some malloc'ed memory. If my code always ensures that pwrite and pread point within that array or one past it, then I am fairly confident that ex.pwrite - ex.pread will always be defined. However, what if pwrite and pread are both NULL. Can I just expect subtracting the two is defined as (ptrdiff_t)0 or does strictly compliant

I want to define an inline function in a project, compiled with c99. How can I do it? When I declare the function in a header file and give the detail in a .c file, the definition isn't recognized by other files. When I put the explicit function in a header file, I have a problem because all .o files who use it have a copy of the definition, so the linker gives me a "multiple definition" error. What I am trying to do is something like: header.h inline void func() { do things... } lib1.c #include "header.h" ... lib2.c #include "header.h" with a utility which uses both lib1.o and lib2.o

This question was triggered by replie(s) to a post by Herb Sutter where he explained MS's decision to not support/make a C99 compiler but just go with the C(99) features that are in the C++(11) standard anyway. One commenter replied : (...) C is important and deserves at least a little bit of attention. There is a LOT of existing code out there that is valid C but is not valid C++. That code is not likely to be rewritten (...) Since I only program in MS C++, I really don't know "pure" C that well, i.e. I have no ready picture of what details of the C++-language I'm using are not in C(99) and I

What happens in C when you create an array of negative length? For instance: int n = -35; int testArray[n]; for(int i = 0; i < 10; i++) testArray[i]=i+1; This code will compile (and brings up no warnings with -Wall enabled), and it seems you can assign to testArray[0] without issue. Assigning past that gives either a segfault or illegal instruction error, and reading anything from the array says "Abort trap" (I'm not familiar with that one). I realize this is somewhat academic, and would (hopefully) never come up in real life, but is there any particular way that the C standard says to treat