Trait bounds for type inference

[tisonkun]

So far, we have only Unbounded to bound the supported types.

However, this may cause issues like (ref):

BSize::kib(16_u64); // compile failed; multiple applicable items in scope
BSize::<u64>::kib(16_u64); // compiled

I'm considering to change the unsigned.rs file to bounds.rs and add a series of trait bounds:

ByteSize = the current Unsigned
SupportKB = [u16, u32, u64, usize]
SupportKiB = [u16, u32, u64, usize]
SupportMB = [u32, u64, usize]
SupportMiB = [u32, u64, usize]
...

Let me demonstrate a changeset and see if it works well or adds too much type noise.

[tisonkun]

Blocked by

• Tracking Issue for const_ops rust-lang/rust#143802
• Tracking Issue for RFC 3762, "Make trait methods callable in const contexts" rust-lang/rust#143874

[tisonkun]

Partially resolved by #13.

We do need to wait for Rust stdlib's stablization for formally release these.

[tisonkun]

#16 renames the generic wrapper to ByteSize and defines a series of type aliases:

• BSize = ByteSize<usize>
• BSize8 = ByteSize<u8>
• BSize16 = ByteSize<u16>
• BSize32 = ByteSize<u32>
• BSize64 = ByteSize<u64>

The ergonomics should be much better now.

[tisonkun]

This should be the final blocker before we call a 1.0 release. That is, once Rust stabilizes all the nightly features we need, we can drop the "nightly" feature flag and cut a 1.0 release.