Make Uint256::from_{le,be}_bytes and ::new const #1071
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| pub const fn from_be_bytes(data: [u8; 32]) -> Self { | ||
| let words: [u64; 4] = [ | ||
| u64::from_le_bytes([ | ||
| data[31], data[30], data[29], data[28], data[27], data[26], data[25], data[24], | ||
| ]), | ||
| u64::from_le_bytes([ | ||
| data[23], data[22], data[21], data[20], data[19], data[18], data[17], data[16], | ||
| ]), | ||
| u64::from_le_bytes([ | ||
| data[15], data[14], data[13], data[12], data[11], data[10], data[9], data[8], | ||
| ]), | ||
| u64::from_le_bytes([ | ||
| data[7], data[6], data[5], data[4], data[3], data[2], data[1], data[0], | ||
| ]), | ||
| ]; | ||
| Uint256(U256(words)) | ||
| } |
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I feel embarrassed I didn't think of the simple solution here. I tried to slice the data and failed because I couldn't transform/convert it in a const context.
Nice!
| 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, | ||
| 0, 0, 42, | ||
| ]); | ||
| assert_eq!(a, Uint256::from(42u128)); |
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This is a PoC. Testing is incomplete and we also want a version for big endian in order to makenewconst.Based on #1073