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### 3122. `__cpp_lib_chrono_udls` was accidentally dropped

Section: 17.3.1 [support.limits.general] Status: C++20 Submitter: Stephan T. Lavavej Opened: 2018-06-14 Last modified: 2021-02-25

Priority: 0

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Discussion:

Between P0941R0 and P0941R1/P0941R2, the feature-test macro `__cpp_lib_chrono_udls` was dropped. It wasn't mentioned in the changelog, and Jonathan Wakely and I believe that this was unintentional.

[2018-06-23 Moved to Tentatively Ready after 5 positive votes on c++std-lib.]

[2018-11, Adopted in San Diego]

Proposed resolution:

This wording is relative to the post-Rapperswil 2018 working draft.

In 17.3.1 [support.limits.general], "Table ??? - Standard library feature-test macros", add the following row:

> Table ??? — Standard library feature-test macros
> Macro name | Value | Headers
> --- | --- | ---
> `[…]`
> `__cpp_lib_chrono_udls` | `201304L` | `<chrono>`
> `[…]`