Dominikus Dittes Scherkl:
I would recommend to use something like this:
/// returns the number of the highest set bit +1 in the given
value or 0 if no bit is set
size_t bitlen(T)(const(T) a) pure @safe @nogc nothrow
if(isUnsigned!T)
{
static if(T.sizeof <= size_t.sizeof) // doesn't work for
ulong on 32bit sys
{
return x ? core.bitop.bsr(x)+1 : 0;
}
else static if(T.sizeof == 8) // ulong if size_t == uint
{
return x ? x>>32 ? core.bitop.bsr(x)+33 :
core.bitop.bsr(x)+1 : 0;
}
}
Is this good to be added to Phobos? Perhaps with a more
descriptive name?
Bye,
bearophile
