'C makes it easy to shoot yourself in the foot. C++ makes it harder, but when you do, it blows away your whole leg.'  -Bjarne Stroustrup

Reference : http://www.open-std.org/JTC1/SC22/WG14/www/docs/n1256.pdf

  
  ed2k://|file|n1256.pdf|3788603|a728a3c5e98e681a8c389ffc46640625|
  
  

===== DEVEL / C =====

  * [[Book]] http://www.acm.uiuc.edu/webmonkeys/book/c_guide/
  * isbn:2100487345  [[French]] [[Livre]]
  * http://www.strath.ac.uk/IT/Docs/Ccourse/ccourse.html # C course
  * http://directory.google.com/Top/Computers/Programming/Languages/C/
  * http://www.faqs.org/faqs/C-faq/
  * https://en.wikipedia.org/wiki/MISRA_C# ConventioN

==== [[Langage]] Keywords : ====

  * if else
  * for while do
  * return
  * struct typedef enum
  * [[sizeof]]
  * main


==== TYPES ====

  * special type "void" which is not really a type
  * lang defined basic types : char, short, int, void, long, double


On X86 architechure (running [[Linux]] or [[Windows]] ) :

  # sizeof(char)=1
  # sizeof(void)=1 @ gcc@[[Linux]] & 0 @ [[MSVC]]@[[Windows]]

  # sizeof(short)=2

  # sizeof(int)=4
  # sizeof(void*)=4
  # sizeof(char*)=4
  # sizeof(long int)=4
  # sizeof(long)=4

  # sizeof(double)=8
  # sizeof(long long)=8 // long long is not ansi and not supported by msvc

  * arrays and pointers , char ptr[] ~=~ char* ptr

  * structures :
  struct buffer { unsigned int size_; char* pbytes_; }

  * enum
  enum colors { RED=1, YELLOW, GREEN=6, BLUE };

Now RED=1, YELLOW=2, GREEN=6 and BLUE=7.

The main advantage of enum is that if you don't initialize your constants,
each one would have a unique value. The first would be zero and the rest would
then count upwards.

  * [[typedef]]

  T limitmax = ((tmp=~0)==(tmp>>1)?~(tmp<<((sizeof(tmp)<<3)-1)):tmp);


==== ARRAYS ====

[[C]] & [[C++]] only support:

  int w[[]] = {1,2,3};

[[Java]] supports both :
  int[[]] v = {1,2,3};
  int w[[]] = {1,2,3};

  //static allocation (on compile time)
  static char img[[h]][[w]][[IMAGE_DEPTH]];
  img[[h]][[w]][[k]] = 'a';
  unsigned char* ptr = &img[[0]][[0]][[0]];

  // dynamic allocation (on run
  pimg = new char[[h*w*IMAGE_DEPTH]]; time)
  pimg[[(ih*w*IMAGE_DEPTH)+(iw*IMAGE_DEPTH)+k]] = 'a' ;

  // both are stored the same in RAM
  memcmp( ( char*) pimg, ( char*) ptr, h*w*IMAGE_DEPTH) ); // =0 //same

See how array can be usefull

  int f(int c[[]][[2]] ) { c[[0]][[0]] = 1; }

  int main(int argc, char* argv[[]]) {
  int a[[1]][[2]];
  a[[0]][[0]] = 0;
  f(a);
  debugi( a[[0]][[0]] ); //1
  }


==== OPERATORS ====

[[Bit]] MASK :

  int reverseColor_ARGB_to_BGRA(int c)
  {
  int b= c &0xFF;
  int g = (c>>8) &0xFF;
  int r = (c>>16) &0xFF;
  int a = (c>>24) &0xFF;

  // return ( a | (r<<8) | (g<<16) | (b<<24) ); // may be unsafe

  return ( a
  | ( (r<<8) &0xFF00 )
  | ( (g<<16) &0xFF0000 )
  | ( (b<<24) &0xFF000000 )
  );

  }

  * bitfield : http://tastalian.free.fr/index.php?index=10
  * http://linuxfr.org/2006/09/07/21299.html # [[Bit]]


==== POINTERS ====

<RzR> can you tell why in std libs they use : "const char *" while "char const *
const" ...could be used

<The_Vulture> RzR: because the other const just makes the pointer itself
const, and since it's passed by value, that wouldn't make a difference to the
caller

<The_Vulture> an implementation could add or remove the extra const without
making any difference to the caller

<RzR> your answser is smart

http://www.goingware.com/tips/member-pointers.html


==== API ====

  * http://altdevblogaday.org/2011/02/12/alternatives-to-malloc-and-new/# [[libc]]
  * http://www.greenend.org.uk/rjk/2001/06/poll.html
  * http://www.di.unipi.it/~nids/docs/longjump_try_trow_catch.html# [[jmp]]

@tag: [[libc]] [[api]] [[socket]]

==== [[OOP]] IN C ====

return-type function-name(paramater-type-list);
int (*aaron(char *(*)(void)) (long, int);

''Defines the function aaron which returns a pointer to a function.
The function aaron takes one argument: a pointer to a function
which returns a character pointer and takes no arguments.
The returned function returns a type int
and has two parameters of type long and int.''

  * http://ldeniau.home.cern.ch/ldeniau/html/oopc/oopc.html
  * http://www.function-pointer.org/fpt.html#defi
  * http://xinehq.de/index.php/hackersguide#AEN384

typedef struct my_stack_s my_class_t;

  struct my_stack_s {
  /* method "push" with one parameter and no return value */
  void (*push)(my_stack_t *this, int i);

  /* method "add" with no parameters and no return value */
  void (*add)(my_stack_t *this);

  /* method "pop" with no parameters (except "this") and a return value */
  int (*pop) (my_stack_t *this);
  }; 

  /* constructor */
  my_class_t *new_my_stack(void);


==== [[printf]] ====

  cat > main.c << EOF && make main && ./main
  p="p=%c%s%c;main(){printf(p,34,p,34);}";main(){printf(p,34,p,34);}
  EOF


==== operators ====

i++ vs ++i ?

++i does not create a temp object and addition, so it is better and faster 


===== MISC =====

[[CPU]] : simd : http://ds9a.nl/gcc-simd/
http://gcc.gnu.org/onlinedocs/gcc-3.4.0/gcc/X86-Built-in-Functions.html

  * [[optimize]] : http://www.eventhelix.com/realtimemantra/basics/optimizingcandcppcode.htm#Don%27t%20Define%20a%20Return%20Value%20if%20not%20Used

http://msdn.microsoft.com/library/default.asp?url=/library/en-us/gdi/bitmaps_0zn6.asp
have fun of bmiColors[[1]];

<mornifle> le mieux etant de lire le header xmmintrin.h

  * http://www.etalabs.net/compare_libcs.html

  * http://personal.ee.surrey.ac.uk/Personal/R.Bowden/C/test/selftest.html
  * http://www.cquestions.com/2012/02/tricky-c-questions-and-answers.html

===== MorE =====

@TaG: LangC [[CPlusPlus]] [[C++]] [[GCC]] [[MSVC]] [[Programming]] [[Maths]] [[Preprocessor]] [[static]] [[typedef]] [[Preprocessor]] [[Unix]] [[lang]] [[std]] [[ptr]] [[pointer]] [[oop]] UnioN

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