Macro identify_callsite

Statically constructs an Identifier for the provided Callsite.

This may be used in contexts such as static initializers.

For example:

use tracing_core::{callsite, identify_callsite};
# use tracing_core::{Metadata, subscriber::Interest};
# fn main() {
pub struct MyCallsite {
   // ...
}
impl callsite::Callsite for MyCallsite {
# fn set_interest(&self, _: Interest) { unimplemented!() }
# fn metadata(&self) -> &Metadata { unimplemented!() }
    // ...
}

static CALLSITE: MyCallsite = MyCallsite {
    // ...
};

static CALLSITE_ID: callsite::Identifier = identify_callsite!(&CALLSITE);
# }