Add support for casting between numeric types #576
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cburgdorf
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cburgdorf
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Oct 20, 2021
| # | ||
| # Notice that Rust does allow the transition in one | ||
| # step and apparently size is changed before the sign: | ||
| # https://play.rust-lang.org/?version=stable&mode=debug&edition=2018&gist=cfc82437a365ca1f534a40f5182bd1e2 |
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This whole thing caught me by surprise. Found it in the solidity docs and then validated it with Rust. Decided that it would be good to follow Solidity with that stricter checking.
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sbillig
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What was wrong?
There's currently no way to convert between different numeric types.
How was it fixed?
Added support for explicit type casting such as
u16(some_u8_value). Type casting between any numeric types is allowed (which means types may be truncated) but it is a type error to change both the sign and the size at the same time. This is inspired by Solidity which handles it the same way. It does mean that we diverge from Rust here but I think that being more strict is the right thing for us to do here.