Moderators: hgm, Rebel, chrisw
But where is the code that defines EmptyHistory?mcostalba wrote:MattieShoes wrote:Haha, I write in C++ and use memset all the time. Is there some simpler C++ alternative to this to zero out a history table?Code: Select all
memset(history, 0, sizeof(history));Code: Select all
*history = EmptyHistory;
Just for the pleasure of pumping gas into our little flame war, I show you the words of Linus Torvalds:Bo Persson wrote:It teaches the use of the C++ standard library, containers, iterators, overloads, generic functions, and user defined classes, before going into the really difficult stuff like pointers and arrays.
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There is a lot of C that is of very little use, once you have learned the better ways of C++. So start there!
http://thread.gmane.org/gmane.comp.vers ... ocus=57918C++ is a horrible language. It's made more horrible by the fact that a lot of substandard programmers use it, to the point where it's much much easier to generate total and utter crap with it. Quite frankly, even if the choice of C were to do *nothing* but keep the C++ programmers out, that in itself would be a huge reason to use C.
Funny you should bring that up as an example. From http://horstmann.com/When I first leaned C over thirty years ago, I was struck by the resemblance of scanf()/printf() functions with the horrible old Fortran read/write/format statements. I thought to myself that there must be a better way, and the C++ formatted character streams are that better way.
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The March of Progress
1980: C
printf("%10.2f", x);
1988: C++
cout << setw(10) << setprecision(2) << showpoint << x;
1996: Java
java.text.NumberFormat formatter = java.text.NumberFormat.getNumberInstance(); formatter.setMinimumFractionDigits(2); formatter.setMaximumFractionDigits(2); String s = formatter.format(x); for (int i = s.length(); i < 10; i++) System.out.print(' '); System.out.print(s);
2004: Java
System.out.printf("%10.2f", x);
2008: Scala and Groovy
printf("%10.2f", x)
Does memcpy() copy one byte at a time?sje wrote:Some compilers like g++ will use calls to memcpy() as code for the default copy constructor and for (part of) the code for the default assignment operator. This is okay, but for speed it's sometimes better to provide explicit definitions that copy more than one byte at a time.
That's somewhat similar to the hilarious The Evolution of a Programmer. But as always, Haskell is more fun. I particularly like the "Ph.D. Haskell Programmer" and the "Post-doc Haskell Programmer".Gian-Carlo Pascutto wrote:Funny you should bring that up as an example. From http://horstmann.com/When I first leaned C over thirty years ago, I was struck by the resemblance of scanf()/printf() functions with the horrible old Fortran read/write/format statements. I thought to myself that there must be a better way, and the C++ formatted character streams are that better way.
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The March of Progress 1980: C printf("%10.2f", x); 1988: C++ cout << setw(10) << setprecision(2) << showpoint << x; 1996: Java java.text.NumberFormat formatter = java.text.NumberFormat.getNumberInstance(); formatter.setMinimumFractionDigits(2); formatter.setMaximumFractionDigits(2); String s = formatter.format(x); for (int i = s.length(); i < 10; i++) System.out.print(' '); System.out.print(s); 2004: Java System.out.printf("%10.2f", x); 2008: Scala and Groovy printf("%10.2f", x)
Well, memcpy() can copy one byte at a time; see the man page.mcostalba wrote:Does memcpy() copy one byte at a time?sje wrote:Some compilers like g++ will use calls to memcpy() as code for the default copy constructor and for (part of) the code for the default assignment operator. This is okay, but for speed it's sometimes better to provide explicit definitions that copy more than one byte at a time.
Heh. Actually, I always explicitly code the package name:Gian-Carlo Pascutto wrote:Funny you should bring that up as an example. From http://horstmann.com/When I first leaned C over thirty years ago, I was struck by the resemblance of scanf()/printf() functions with the horrible old Fortran read/write/format statements. I thought to myself that there must be a better way, and the C++ formatted character streams are that better way.
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The March of Progress 1980: C printf("%10.2f", x); 1988: C++ cout << setw(10) << setprecision(2) << showpoint << x; 1996: Java java.text.NumberFormat formatter = java.text.NumberFormat.getNumberInstance(); formatter.setMinimumFractionDigits(2); formatter.setMaximumFractionDigits(2); String s = formatter.format(x); for (int i = s.length(); i < 10; i++) System.out.print(' '); System.out.print(s); 2004: Java System.out.printf("%10.2f", x); 2008: Scala and Groovy printf("%10.2f", x)
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std::cout << std::setw(10) << std::setprecision(2) << std::showpoint << x;
It depends on your compiler!sje wrote:Well, memcpy() can copy one byte at a time; see the man page.mcostalba wrote:Does memcpy() copy one byte at a time?sje wrote:Some compilers like g++ will use calls to memcpy() as code for the default copy constructor and for (part of) the code for the default assignment operator. This is okay, but for speed it's sometimes better to provide explicit definitions that copy more than one byte at a time.
If memcpy can optimize by copying multiple bytes per iteration, then it must figure sizes and maybe alignments at run time. I doubt that this happens. Handling the general case is usually the most expensive approach. Also, it's not guaranteed that memcpy() will be expanded inline, so it has some call overhead as well.
, it will inline optimized code. That's funny!Gian-Carlo Pascutto wrote:Funny you should bring that up as an example. From http://horstmann.com/When I first leaned C over thirty years ago, I was struck by the resemblance of scanf()/printf() functions with the horrible old Fortran read/write/format statements. I thought to myself that there must be a better way, and the C++ formatted character streams are that better way.
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The March of Progress 1980: C printf("%10.2f", x); 1988: C++ cout << setw(10) << setprecision(2) << showpoint << x; 1996: Java java.text.NumberFormat formatter = java.text.NumberFormat.getNumberInstance(); formatter.setMinimumFractionDigits(2); formatter.setMaximumFractionDigits(2); String s = formatter.format(x); for (int i = s.length(); i < 10; i++) System.out.print(' '); System.out.print(s); 2004: Java System.out.printf("%10.2f", x); 2008: Scala and Groovy printf("%10.2f", x)
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// In C++
Chess::Move CurrentMove;
std::cout << CurrentMove;
/* or in C */
printf("what goes here", &CurrentMove);