Migrate from lazy_static crate to std::sync::LazyLock

[jaudiger]

lazy_static!, while a declarative macro, is a macro nonetheless. It can add quite a bit of additional compilation time cost. once_cell::sync::Lazy does the same thing with generics, and can be used more flexibly (i.e. non-static lazily initialised values), and has been proposed to be added to std: rust-lang/rfcs#2788.

Famous Rust projects already did the transition, such as:

• Replace lazy_static with once_cell tokio-rs/tokio#3187
• Migrate from lazy_static to once_cell tokio-rs/tracing#2147

Edit: Since the opening of this issue, a lot of things has happened in Rust, and with Rust 1.80.0, std::sync::LazyLock has been stabilised (see https://doc.rust-lang.org/std/sync/struct.LazyLock.html). There is no need anymore to rely on a crate to lazy initialised a value that is thread safe, everything can now be managed from Rust std 🚀

[lucab]

Thanks for the report. Sounds like a good idea! I'll be happy to review a patch doing this if anybody wants to tackle it.

[jaudiger]

Hi @lucab, thanks, I just opened a PR for it !

[ThomasHabets]

I just opened another PR to use LazyLock from std, instead of a dependency crate alltogether. #556

[ThomasHabets]

This issue should either be closed, or changed to say to move to std::sync::LazyLock

[jaudiger]

This issue should either be closed, or changed to say to move to std::sync::LazyLock

Thanks @ThomasHabets, you are right, I just updated this issue to better reflect the latest alternative with Rust std.