etl/docs/chrono/chrono-literals.md
John Wellbelove 4a88884b39
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---------

Co-authored-by: Roland Reichwein <Roland.Reichwein@bmw.de>
Co-authored-by: John Wellbelove <john.wellbelove@etlcpp.com>
Co-authored-by: John Wellbelove <john.wellbelove@etlcpp.co.uk>
2026-06-06 13:12:44 +01:00

1.6 KiB

title
Chrono literals

{{< callout type="info">}} Header: chrono.h
From: 20.41.0
Similar to: std::literals::chrono_literals {{< /callout >}}

The ETL Chrono literals are define slightly differently from the STL in that they are user defined, as opposed to language defined.

Example
For STL, the literal to define year 2025 would be 2025y. For ETL, the literal is 2025_y.

By default, the ETL uses the designations of the STL.
As this may clash with other user defined literals, the ETL allows more verbose forms to be used, by defining the macro ETL_USE_VERBOSE_CHRONO_LITERALS.
If enabled, the example of 2025_y would be written as 2025_year.

Duration type STL like Verbose
etl::chrono::year 2025_y 2025_year
etl::chrono::day 10_d 10_day
etl::chrono::hours 14_h 14_hours
etl::chrono::minutes 30_min 30_minutes
etl::chrono::seconds 45_s 45_seconds
etl::chrono::milliseconds 500_ms 500_milliseconds
etl::chrono::microseconds 500_us 500_microseconds
etl::chrono::nanoseconds 500_ns 500_nanoseconds

Chrono literals may by accessed by using one of the following namespaces.

using namespace etl::chrono;
using namespace etl::literals;
using namespace etl::chrono_literals;