C ++中'和'，'或'等关键字的目的是什么？

Question

What is the purpose of the following keywords?

and      bitand   compl   not_eq   or_eq   xor_eq
and_eq   bitor    not     or       xor

If all they are is a direct equivalent of:

&&       &        ~       !=       |=      ^=
&=       |        !       ||       ^

Answer 1

http://en.wikipedia.org/wiki/Iso646.h

iso646.h "...defines a number of macros which allow programmers to use C language bitwise and logical operators, which, without the header file, cannot be quickly or easily typed on some international and non-QWERTY keyboards.

The filename refers to the ISO646 standard, a 7-bit character set with a number of regional variations, some of which have accented characters in place of the punctuation marks used by C operators."

Answer 2

Its so you can write crazy code poems like:

class jack
{
   jack();
   jack( jack & jill );
   jack& came_tumbling( int after );
   jack& fell( jack & jill ); 
   jack& operator &= ( jack & jill );
   jack& operator & ( jack & jill );
}

void to_fetch( int pail );

int a_pail;
int after;
jack broke_his_crown;
jack went_up_the_hill;
jack down;

jack and jill = went_up_the_hill;
to_fetch( a_pail ); // of water
jack fell( down and broke_his_crown 
and jill.came_tumbling( after ));