Split the `dec2flt::RawFloat` trait for easier reuse by tgross35 · Pull Request #151905 · rust-lang/rust

tgross35 · 2026-01-31T11:33:17Z

RawFloat is an internal trait with quite a few useful float properties. It currently resides in the dec2flt module but is also used in parsing, and would be nice to reuse other places. Unfortunately it cannot be implemented on f128 because of limitations with how the parsing API is implemented (mantissa must fit into a u64).

To make the trait easier to work with, split it into the following:

Float: Anything that is reasonably applicable to all floating point types.
FloatExt: Items that should be part of Float but don't work for all float types. This will eventually be merged back into Float once it can be implemented on f128.
Lemire: Items that are specific to the Lemire dec2flt algorithm.

These traits are then moved to places that make sense.

Builds on top of #151900

rustbot · 2026-01-31T11:33:20Z

triagebot.toml has been modified, there may have been changes to the review queue.

cc @davidtwco, @wesleywiser

rustbot · 2026-01-31T11:33:22Z

r? @scottmcm

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tgross35 · 2026-01-31T11:33:47Z

The first two commits can be ignored since they are part of #151900

tgross35 · 2026-02-13T13:12:43Z

Yay, this one is ready too

@rustbot ready

This is stacked on on #151900 so the last few (smaller) commits are the relevant bit here.

This is more consistent with what the trait is called elsewhere in tree (specifically compiler-builtins and test-float-parse).

`RawFloat` is currently used specifically for the implementation of the lemire algorithm, but it is useful for more than that. Split it into three different traits: * `Float`: Anything that is reasonably applicable to all floating point types. * `FloatExt`: Items that should be part of `Float` but don't work for all float types. This will eventually be merged back into `Float`. * `Lemire`: Items that are specific to the Lemire algorithm.

`Float` and `FloatExt` are already used by both parsing and printing, so move them out of `dec2flt` to a new module in `num::imp`. `Int` `Cast` have the potential to be used more places in the future, so move them there as well. `Lemire` is the only remaining trait; since it is small, move it into the `dec2flt` root. The `fmt::LowerExp` bound is removed from `Float` here since the trait is moving into a module without `#[cfg(not(no_fp_fmt_parse))]` and it isn't implemented with that config (it's not easily possible to add `cfg` attributes to a single supertrait, unfortunately). This isn't a problem since it isn't actually being used.

rustbot · 2026-03-14T09:35:15Z

This PR was rebased onto a different main commit. Here's a range-diff highlighting what actually changed.

Rebasing is a normal part of keeping PRs up to date, so no action is needed—this note is just to help reviewers.

tgross35 · 2026-03-14T10:05:37Z

@rustbot reroll

Mark-Simulacrum · 2026-03-19T02:28:26Z

@bors r+ rollup

rust-bors · 2026-03-19T02:28:41Z

📌 Commit bec94a3 has been approved by Mark-Simulacrum

It is now in the queue for this repository.

…mulacrum Split the `dec2flt::RawFloat` trait for easier reuse `RawFloat` is an internal trait with quite a few useful float properties. It currently resides in the `dec2flt` module but is also used in parsing, and would be nice to reuse other places. Unfortunately it cannot be implemented on `f128` because of limitations with how the parsing API is implemented (mantissa must fit into a u64). To make the trait easier to work with, split it into the following: * `Float`: Anything that is reasonably applicable to all floating point types. * `FloatExt`: Items that should be part of `Float` but don't work for all float types. This will eventually be merged back into `Float` once it can be implemented on f128. * `Lemire`: Items that are specific to the Lemire dec2flt algorithm. These traits are then moved to places that make sense. Builds on top of rust-lang#151900

…uwer Rollup of 12 pull requests Successful merges: - #152870 (Do not enable split debuginfo for windows-gnu) - #153333 (Fix bootstrap rust build failure for vxworks) - #153681 (ci: add runners for vanilla LLVM 22) - #153824 (Add `Wake` diagnostic item for `alloc::task::Wake`) - #154077 (Optimize 128-bit integer formatting) - #154078 (`define_callbacks` tweaks) - #151905 (Split the `dec2flt::RawFloat` trait for easier reuse) - #153170 (Add is_disconnected functions to mpsc and mpmc channels) - #153804 (Derive Macro Eq: link to more detailed documentation) - #153974 (Point at return type when it is the source of the type expectation) - #154018 (simplify and remove `tests/ui/kindck` and related tests) - #154041 (bootstrap: Allow `--bless`ing changes to editor settings files)

…mulacrum Split the `dec2flt::RawFloat` trait for easier reuse `RawFloat` is an internal trait with quite a few useful float properties. It currently resides in the `dec2flt` module but is also used in parsing, and would be nice to reuse other places. Unfortunately it cannot be implemented on `f128` because of limitations with how the parsing API is implemented (mantissa must fit into a u64). To make the trait easier to work with, split it into the following: * `Float`: Anything that is reasonably applicable to all floating point types. * `FloatExt`: Items that should be part of `Float` but don't work for all float types. This will eventually be merged back into `Float` once it can be implemented on f128. * `Lemire`: Items that are specific to the Lemire dec2flt algorithm. These traits are then moved to places that make sense. Builds on top of rust-lang#151900

…uwer Rollup of 19 pull requests Successful merges: - #152870 (Do not enable split debuginfo for windows-gnu) - #153333 (Fix bootstrap rust build failure for vxworks) - #153681 (ci: add runners for vanilla LLVM 22) - #153727 (When single impl can satisfy inference error, suggest type) - #153824 (Add `Wake` diagnostic item for `alloc::task::Wake`) - #154077 (Optimize 128-bit integer formatting) - #154078 (`define_callbacks` tweaks) - #151905 (Split the `dec2flt::RawFloat` trait for easier reuse) - #153170 (Add is_disconnected functions to mpsc and mpmc channels) - #153308 (Add hygiene annotations for tokens in `macro_rules!` bodies) - #153557 (fix inference variables leaking into HIR const literal lowering logic) - #153804 (Derive Macro Eq: link to more detailed documentation) - #153913 (Fix some suggestions of the `for-loops-over-fallibles` lint) - #153974 (Point at return type when it is the source of the type expectation) - #153987 (mGCA: Lower const generic args to infer when needed) - #154018 (simplify and remove `tests/ui/kindck` and related tests) - #154036 (borrowck/type_check: remove helper left-over from unsized locals) - #154038 (merge `regions-outlives-nominal-type-*` tests into one file) - #154041 (bootstrap: Allow `--bless`ing changes to editor settings files)

rustbot added A-meta Area: Issues & PRs about the rust-lang/rust repository itself S-waiting-on-review Status: Awaiting review from the assignee but also interested parties. T-libs Relevant to the library team, which will review and decide on the PR/issue. labels Jan 31, 2026

rustbot assigned scottmcm Jan 31, 2026

tgross35 force-pushed the dec2flt-traits branch from 9837f1e to ec32d31 Compare January 31, 2026 11:36