Comments on: Smart Variable Swapping

By: kat23

kat23 — Fri, 05 Jun 2009 22:53:28 +0000

Sau baga la compilare un -O3 si nu mai risti sa introduci buguri inutile.

By: Sergiu

Sergiu — Mon, 01 Jun 2009 15:31:39 +0000

http://en.wikipedia.org/wiki/XOR_swap_algorithm

Apropo de ce zicea Lucian
The body of this function is sometimes seen incorrectly shortened to if (x != y) *x^=*y^=*x^=*y;. This code has undefined behavior, since it modifies the lvalue *x twice without an intervening sequence point.

By: AlexJ

AlexJ — Sun, 31 May 2009 15:44:38 +0000

@Sabin: http://en.wikipedia.org/wiki/C_preprocessor caută ‘while(0)”

By: Boboc Sabin

Boboc Sabin — Sun, 31 May 2009 14:52:20 +0000

Salut, de partea cu XOR stiam si eu insa, citisem intr-o carte, cred ca se numea “hacker’s delight” ca poti folosi XOR insa numa pentru tipul de date int. As fi interesat daca poti explica putin treaba cu best practice.
Multumesc, cu respect Boboc Sabin !

By: Lucian

Lucian — Sun, 31 May 2009 14:00:33 +0000

Nu merge cu pointeri, trebuie sa faci cast la ceva.
Şi în plus, e prea lung:

a = a^b^(b=a);

a^=b^=a^=b;