# Standard complex number in std library
**URL:** https://internals.rust-lang.org/t/standard-complex-number-in-std-library/23748
**Category:** language design
**Created:** [November 21, 2025, 7:29pm UTC](https://internals.rust-lang.org/t/standard-complex-number-in-std-library/23748 "2025-11-21T19:29:19Z")
**Posts on this page:** 5
**Page:** 2
### Author:  [@daniel-pfeiffer](https://internals.rust-lang.org/u/daniel-pfeiffer)
#### Post date: [November 24, 2025, 9:59am UTC](https://internals.rust-lang.org/t/standard-complex-number-in-std-library/23748/23 "2025-11-24T09:59:16Z")
> [@Maxwell0EM](#):
>
> for rationals and fixed point numbers, they are just numbers that are not integers, and they can be represented by float point well.
The whole point of specific implementations for rationals and fixed point numbers, is precisely that floats are horrible at representing them. How many beginners fall into the trap of storing currency as float… Absolute no-go for financials!
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### Author:  [@SciMind2460](https://internals.rust-lang.org/u/SciMind2460)
#### Post date: [November 24, 2025, 10:31am UTC](https://internals.rust-lang.org/t/standard-complex-number-in-std-library/23748/24 "2025-11-24T10:31:27Z")
By the way, can anyone provide an example of code that this would benefit? Just asking as I am working on an ACP.
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### Author:  [@bettertree](https://internals.rust-lang.org/u/bettertree)
#### Post date: [February 3, 2026, 1:06pm UTC](https://internals.rust-lang.org/t/standard-complex-number-in-std-library/23748/25 "2026-02-03T13:06:22Z")
Linking to your ACP, transitioned into an RFC:
> [@Complex Numbers (Pre-ACP)](https://internals.rust-lang.org/t/complex-numbers-pre-acp/23769):
>
> Continuing the discussion from [Standard complex number in std library](https://internals.rust-lang.org/t/standard-complex-number-in-std-library/23748)Proposal Problem statement Currently, there is no stable counterpart to the C \_Complex types, and a myriad of implementations exist on [crates.io](http://crates.io). Popular crates like num-complex exist, but more often there are implementations defined by the crates themselves, which, while compatible with the other types in having the exact same implementation, require a myriad of conversion functions to convert with each other. Additionally,…
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### Author:  [@SciMind2460](https://internals.rust-lang.org/u/SciMind2460)
#### Post date: [March 18, 2026, 8:17am UTC](https://internals.rust-lang.org/t/standard-complex-number-in-std-library/23748/26 "2026-03-18T08:17:34Z")
The RFC has been accepted! 🎊 Thank you all of you for your support in helping push this feature forward! [Tracking issue here](https://github.com/rust-lang/rust/issues/154023)
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### Author:  [@MusicalNinjaDad](https://internals.rust-lang.org/u/MusicalNinjaDad)
#### Post date: [April 2, 2026, 12:35pm UTC](https://internals.rust-lang.org/t/standard-complex-number-in-std-library/23748/27 "2026-04-02T12:35:25Z")
That's wonderful. I can offer to support implementation (and have also commented on the tracking issue) if that is useful / wanted.
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