C++ operator and pointer question.plz help me

[xiuuao]

%=, >>=, <<=, &=, ^=, |=
what do these operators mean?
And what are the functions of these operators?

And also in the C++ tutorial provided in this website,
http://www.cplusplus.com/doc/tutorial/pointers/
in the [void pointer] section of this page,
i don't understand the program example demonstrated.
Why the parentheses should be placed like this ->> (char*)data / (int*)data ?
Why can't i place the parentheses like this ->> (char* data) /(int* data) ?

Sorry for the grammatical mistakes and thanks for the help :) .

[The program I mentioned above]
---------------------------------------------------
// increaser
#include <iostream>
using namespace std;

void increase (void* data, int psize)
{
if ( psize == sizeof(char) )
{ char* pchar; pchar=(char*)data; ++(*pchar); }
else if (psize == sizeof(int) )
{ int* pint; pint=(int*)data; ++(*pint); }
}

int main ()
{
char a = 'x';
int b = 1602;
increase (&a,sizeof(a));
increase (&b,sizeof(b));
cout << a << ", " << b << endl;
return 0;
}
--------------------------------------------------

[Peter87]

xiuuao wrote:

%=, >>=, <<=, &=, ^=, |=
what do these operators mean?
And what are the functions of these operators?

If X is one of the operators %, >>, <<, &, ^, | then writing a X= b; has the same meaning as a = a X b;.

xiuuao wrote:

i don't understand the program example demonstrated.
Why the parentheses should be placed like this ->> (char*)data / (int*)data ?
Why can't i place the parentheses like this ->> (char* data) /(int* data) ?

It's the way C-casts are written. The type that you want to cast to inside parentheses. Writing char* data declares a char pointer named data. Putting declarations inside parentheses is only allowed in some cases and is very different from a cast.

[xiuuao]

Thx a lot ,man:)

[EwCjE3v7]

Check this out just scroll down
http://www.cplusplus.com/doc/tutorial/operators/

[xiuuao]

Bitwise Operators ( &, |, ^, ~, <<, >> )

Bitwise operators modify variables considering the bit patterns that represent the values they store.

operator asm equivalent description
& AND Bitwise AND
| OR Bitwise Inclusive OR
^ XOR Bitwise Exclusive OR
~ NOT Unary complement (bit inversion)
<< SHL Shift Left
>> SHR Shift Right
=================================================
As there are no examples in this section[Bitwise operators ]
not sure what the actual function of these operators are in C++ :(
~,>> and <<

I tested on my computer and still not know how and when to use it.
Are they just not common operators used in programming?

[Peter87]

Bitwise operators are often used when you care about the bits of a variable and not necessary the numerical value they represent.

Read this: http://en.wikipedia.org/wiki/Bitwise_operators

[Chervil]

Another tutorial: http://www.cprogramming.com/tutorial/bitwise_operators.html

[EwCjE3v7]

Do you have any c++ book..I'm sure they are in there..if not u can always get an e book