hello, everyone.
I am stuck in solidity 0.8.4
In the picture, How can I replace the "d & -d" for no-error?

-1*d

thank for your reply, but it still doesn't work

change the data type too. Uint = unsigned int (meaning only +ve number)
Chnge it to int which includes both +ve and -ve

something like this.

I found solution
uint256 pow2 = d & ~d;
how about do you think?

0

?

It's always gonna be zero, regardless of d

then what's the solution?

Casting

the standard library is "pow2 = d & (-d)"
Isn't it always zero?

Actually defining what you're doing

I am afraid of making an error

-d is different from ~d

-d uses the two's complement. ~d the one's complement

int_8 d = 39;
int pow2 = d & (int_8(-1)*d);

You are right.
I solved this problem like below
How about do you think?

Looks right. I don't get why you didn't use my code bc it'd save a small amount of gas and be less code but your code looks right too

your code is error

I thought d was a unit_8. It was on the screenshot you showed me

Then just change that uint_8 in my code to uint_256

d is uint256

Oh wait sry i read it wrong. It never was a unit_8

anyway, thanks for you reply
And this is other problem.
Do you know why ganache hangs in open workspace?

Idk what open workspace is

Ganache hangs when opening truffle workspace

https://t.me/dev_solidity/182868

Oh I've never used that. I only use the cli version

do you mean "truffle develop" console?

It's called ganache-cli but has been renamed to just ganache half a year ago

could you explain about usage of ganache-cli?

You enter ganache-cli into a terminal and it starts a dev chain for you

should I install it of course?

what do I have to do?

it will improve vscode terminal speed

Use ganache npm package globally..

npm i -g ganache

then you will find these