Can somebody tell me the difference between #pragma pack(push,1) and __attribute__((packed))? I am getting a compilation error if I use second type of struct packing which says cannot bind packe...

I'm trying to work through an issue on a third party library. The issue is the library uses GCC's nested functions buried in a macro, and Clang does not support nested functions and has no plans to...

I had always thought that variable length arrays were not allowed in c++(Refer :Why aren't variable-length arrays part of the C++ standard?) .But than why does this code compile and work? #inc...

Refering to js0n.c The code syntax is as below: static void *gostruct[] = { [0 ... 255] = &&l_bad, ['\t'] = &&l_loop, [' '] = &&l_loop, ['\r'] = &&l_loop, ['\n...

During my C language practice, I face an expression and then I get it simplified as follows: int a=({10;}); It is a legal expression since it gets past the gcc compiler. Please focus on this pa...

Here is a piece of code in /usr/src/linux-3.10.10-1-ARCH/include/linux/printk.h: static inline int printk_get_level(const char *buffer) { if (buffer[0] == KERN_SOH_ASCII && buffer[1]) { ...

I'm reading about VLAs in C Primer Plus, and this book strictly says that the introduction of VLAs to C began with the C99 standard. Whenever I attempt to declare a loop control variable within the...

GCC has an awesome ternary expression extension to C which allows us to create a statement like this: int x = some_var ?: 10; // expands to some_var ? some_var : 10 Which is really nice, and whi...

I don't understand why this works: /* gcc range extension */ __extension__ static int fn(int n) { switch (n) { case 0: return 0; case 1 ... 1000: return 1; default: return -1; } } But this ...

I'm writing some code that makes use of computed goto. The syntax checker is flagging every instance of goto *ptr and &&label as syntax error. Is there anyway to stop this? Addition by alk...

I came across this weird C++ program. #include <iostream> using namespace std; int main() { int a = ({int x; cin >> x; x;}); cout << a; } Can anyone explain what is going on?...