// // A logical xor operator for C++. // // Create a macro for the following syntax: ((a xor b)). Note that // the bracket are part of the syntax and shall not be removed! // The macro guarantees left-to-right evaluation, a sequence point // between the evaluation of 'a' and 'b', conversion of the // parameters to bool and a boolean result. #define BOOST_DETAIL_XOR(x) !static_cast<bool>(x):static_cast<bool>(x) #define xor )?BOOST_DETAIL_XOR(
// Usage:
#include <iostream> using namespace std;
struct B
{
operator bool() const { return true; }
B operator!() const { return B(); }
};int main()
{
B a, b;// Oops... cout << ( a != b ) << endl; cout << ( a ? !b : !!b ) << endl;
// Works, but long, ugly syntax and repeating 'b': cout << ( a ? !static_cast<bool>(b) : static_cast<bool>(b) ) << endl;
// Cool? cout << (( a xor b )) << endl; }
Regards, Daniel
PS: No, don't take this too serious :o)
-- Daniel Frey
aixigo AG - financial training, research and technology Schloß-Rahe-Straße 15, 52072 Aachen, Germany fon: +49 (0)241 936737-42, fax: +49 (0)241 936737-99 eMail: [EMAIL PROTECTED], web: http://www.aixigo.de
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