Binding-less static procedures?

[mcandre]

Could we get an additional macro pattern for lazy_static! that allows for lambda procs to run, without binding the result to a variable?

[sfackler]

When would the lambda run? lazy_static is called lazy static because the lambda is evaluated on first access. If you want that behavior, you can just make a lazy static of ().

[mcandre]

Interesting empty unit idea! Could we get an example added to the test suite? I'm trying to use the empty unit for this, but my syntax must be wrong somehow.

[sfackler]

Creating a unit lazy static is the same thing as creating a lazy static of any other type - your initializer does some computation and then returns ().

You can also just use the standard library's Once type for this: https://doc.rust-lang.org/std/sync/struct.Once.html

[mcandre]

I'm not sure. Looks like Once expects to run from a function scope, not outside of a function like with lazy_static.

Eh, I'm working around this by no longer creating my main function by macro, but instead inserting my macro into main, where I can also insert my "static" procedure.

Will release a new version of mcandre/tinyrick soon using this to hack together a basic caching dependency task tree.

Thanks again for working hard on lazy_static!

[sfackler]

All code runs from a function scope.

These two code samples are basically equivalent:

static ONCE: Once = Once::new();

fn init_stuff() {
    ONCE.call_once(|| do_stuff());
}

lazy_static! {
    static ref ONCE: () = do_stuff();
}

fn init_stuff() {
    *ONCE
}