Better hygiene for core crate naming (#180)

[tyranron]

Resolves #180

Synopsis

See #180 (comment) for details.

At the moment, compilation fails in a local crate core is present in workspace or some another crate is renamed as core.

Solution

Use ::derive_more::core instead of ::core in macro expansions.

Checklist

• Documentation is updated (not required)
• Tests are added/updated (hard to test)
• CHANGELOG entry is added

[JelteF]

Honestly, I don't think this is worth all this. I think the advice: "don't call your crate core" is good enough.

[tyranron]

@JelteF we already had that episodically here and there across the code base. I don't see any downsides of this, and it doesn't cost us anything, except making the codebase a little bit more consistent.

[JelteF]

This basically starts including all of std in our API surface. Can you check if that has impact on compile times or crate size?

[tyranron]

@JelteF hmm... I don't think that use statements actually include something into crate (it's extern crate which does), rather than just making outside types nameable or accessible from other crates. Furthermore, every Rust toolchain has the core lib being precompiled and extern crated already there. So it's only up to LTO to eliminate redundant code in the final binary.

Anyway, running

cargo bloat --example deny_missing_docs --features full --profile release --crates --split-std

Shows on master:

 File  .text     Size Crate
12.1%  28.3%  58.6KiB std
11.2%  26.1%  54.2KiB core
 7.2%  16.9%  35.1KiB gimli
 5.3%  12.3%  25.5KiB addr2line
 4.6%  10.7%  22.1KiB rustc_demangle
 2.1%   5.0%  10.3KiB [Unknown]
 1.8%   4.2%   8.7KiB alloc
 0.4%   0.9%   1.9KiB object
 0.2%   0.4%     940B memchr
 0.1%   0.2%     432B trybuild
 0.1%   0.1%     272B panic_abort
 0.0%   0.1%     124B basic_toml
 0.0%   0.0%      24B panic_unwind
 0.0%   0.0%       8B libc
 0.0%   0.0%       4B deny_missing_docs
42.8% 100.0% 207.3KiB .text section size, the file size is 484.1KiB

And on this branch:

 File  .text     Size Crate
12.1%  28.3%  58.6KiB std
11.2%  26.1%  54.2KiB core
 7.2%  16.9%  35.1KiB gimli
 5.3%  12.3%  25.5KiB addr2line
 4.6%  10.7%  22.1KiB rustc_demangle
 2.1%   5.0%  10.3KiB [Unknown]
 1.8%   4.2%   8.7KiB alloc
 0.4%   0.9%   1.9KiB object
 0.2%   0.4%     940B memchr
 0.1%   0.2%     432B trybuild
 0.1%   0.1%     272B panic_abort
 0.0%   0.1%     124B basic_toml
 0.0%   0.0%      24B panic_unwind
 0.0%   0.0%       8B libc
 0.0%   0.0%       4B deny_missing_docs
42.8% 100.0% 207.3KiB .text section size, the file size is 484.1KiB

Which doesn't show any meaningful difference.

And for the timings...

master:

$ cargo bloat --example deny_missing_docs --features full --profile release -j 1 --split-std --time
 Time Crate
9.23s trybuild
2.28s derive_more_impl
1.49s serde_json
1.48s serde_derive
1.38s syn
1.38s serde
1.26s basic_toml
0.53s glob
0.38s rustversion
0.37s proc_macro2
0.28s termcolor
0.26s derive_more
0.17s unicode_segmentation
0.15s convert_case
0.14s ryu
0.11s quote
0.08s once_cell
0.07s deny_missing_docs
0.04s unicode_ident
0.04s itoa
0.02s unicode_xid
0.01s static_assertions

this branch:

$ cargo bloat --example deny_missing_docs --features full --profile release -j 1 --split-std --time
 Time Crate
9.22s trybuild
2.25s derive_more_impl
1.49s serde_derive
1.47s serde_json
1.36s syn
1.36s serde
1.27s basic_toml
0.53s glob
0.38s rustversion
0.37s proc_macro2
0.28s termcolor
0.25s derive_more
0.16s unicode_segmentation
0.15s convert_case
0.14s ryu
0.11s quote
0.08s once_cell
0.07s deny_missing_docs
0.04s itoa
0.04s unicode_ident
0.03s unicode_xid
0.01s static_assertions

[JelteF]

I guess this was stupid friday evening thinking of me. Thank you for explaining that this doesn't impact binary size or build time (I guess generating docs would take a lot longer if it wasn't #[doc(hidden)] though)

[JelteF]

I called out one place where maybe one we can use the shorter path, other than that this looks good to me.

[JelteF]

I guess this was stupid friday evening thinking of me. Thank you for explaining that this doesn't impact binary size or build time (I guess generating docs would take a lot longer if it wasn't #[doc(hidden)] though)

[tyranron]

ping @JelteF (needs approve for merge)