once_cell provides two new cell-like types,
might store arbitrary non-
Copy types, can be assigned to at most once and provide direct access
to the stored contents. In a nutshell, API looks roughly like this:
Note that, like with
set method requires only a shared reference.
Because of the single assignment restriction
get can return an
&T instead of
once_cell also has a
Lazy<T> type, build on top of
OnceCell which provides the same API as
lazy_static! macro, but without using any macros:
use ; use Lazy; static GLOBAL_DATA: = new;
More patterns and use-cases are in the docs!
- generic_once_cell (bring your own mutex)
once_cell API are included into
std as of Rust 1.70.0.