Add support for euclidean division and modulation

[SparrowLii]

Fixes #159
Add support for euclidean division and modulation.

[cuviper]

I think we can use FloatCore to avoid the cfg limitations. Otherwise, there are some style issues, but I think this looks pretty good!

[SparrowLii]

Thanks very much for reviewing. I have made the corresponding changes.
As a Rust learner (even an open source learner)， I look forward to contributing to Rust.

[zesterer]

Any reason for this to not use the corresponding method on all integer types?

[SparrowLii]

That's what I did before. But this will cause the test of version 1.8.0 to fail, as it shows that the parameter type of div_eculid/rem_eculid is incorrect (expecting &self, not self, or on the contrary). So I implemented a separate implementation to avoid these compatibility issues.

[XAMPPRocky]

@cuviper Is there anything left in this PR that needs to be changed? We'd really like this functionality for rust-gpu so that we can support rem_euclid on SPIR-V platforms. 🙂

[cuviper]

I think the methods should take references, for the sake of num-bigint where it's a waste of allocations to consume values. Either that, or go fully generic with a type parameter RHS and and associated type Output, so they can be implemented for any mix of values and references. There are annoyance trade-offs both ways.

[SparrowLii]

I think it is reasonable to use reference types from the aspect of efficiency. If a general type is used and the Output type is specified, we need to implement it separately for the several cases(self, &self, rhs, &rhs). This should probably be what a direct user-facing library should do. As a basic library, num-trait should maintain its concise style IMO

[cuviper]

Thanks, it looks nice.

Maybe we should also add a combined div_rem_euclid? (and checked.) That would let you get both values with the divisions and conditions only checked once. All that probably gets optimized together with primitive values anyway, but it would matter for types like BigInt.

[cuviper]

bors r+

[bors]

Build succeeded:

• Format
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• Test (1.15.0)
• Test (1.20.0)
• Test (1.26.0)
• Test (1.31.0)
• Test (1.8.0)
• Test (beta)
• Test (i586)
• Test (nightly)
• Test (stable)