Conversions

[ycscaly]

Implements conversion across different Uxxx types. This allows what was previously e.g.

let u: U128 = transcript.challenge(b"u");

let u: U256 = U128::ZERO.concat(&u);
let u: U512 = U256::ZERO.concat(&u);
let u: U1024 = U512::ZERO.concat(&u);
let u: U2048 = U1024::ZERO.concat(&u);
let u: U4096 = U2048::ZERO.concat(&u);

To become:

let u: U128 = transcript.challenge(b"u");
let u: U4096 = u.to_u4096;

[ycscaly]

Resolves #220

[tarcieri]

It seems like this would be better implemented in terms of the From trait.

[ycscaly]

It seems like this would be better implemented in terms of the From trait.

Agreed

It seems like this would be better implemented in terms of the From trait.

Agreed, this also allowed me to drop the paste dependency.

Should be good now

[ycscaly]

Replaced by #230