• Mike James (16/16) Aug 12 2010 Would it be more useful to have a true integer square root rather than
• Don (4/6) Aug 12 2010 cast(int)sqrt() is MUCH quicker than any other way of doing it. Note

"Mike James" <foo bar.com> writes:

Would it be more useful to have a true integer square root rather than 
overloading the real square root? Something like:

T intsqrt(T)(T i) {
    T bitMask = 1;
    T result = 0;

    bitMask <<= T.sizeof * 4 - 1;

    while (bitMask) {
        result |= bitMask;
        if ((result * result) > i) {
            result &= ~bitMask;
        }
        bitMask >>= 1;
    }

    return result;
}


-=mike=- 

Don <nospam nospam.com> writes:

Mike James wrote:
 Would it be more useful to have a true integer square root rather than 
 overloading the real square root? 

cast(int)sqrt() is MUCH quicker than any other way of doing it. Note 
that overloading sqrt is a temporary hack.
BTW, your code fails for intsqrt(0x8000 * 0x8000) and higher.