| //- |
| // Copyright 2018 Jason Lingle |
| // |
| // Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or |
| // http://www.apache.org/licenses/LICENSE-2.0> or the MIT license |
| // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your |
| // option. This file may not be copied, modified, or distributed |
| // except according to those terms. |
| |
| /// Produce a hashable identifier unique to the particular macro invocation |
| /// which is stable across processes of the same executable. |
| /// |
| /// This is usually the best thing to pass for the `fork_id` argument of |
| /// [`fork`](fn.fork.html). |
| /// |
| /// The type of the expression this macro expands to is |
| /// [`RustyForkId`](struct.RustyForkId.html). |
| #[macro_export] |
| macro_rules! rusty_fork_id { () => { { |
| struct _RustyForkId; |
| $crate::RustyForkId::of(::std::any::TypeId::of::<_RustyForkId>()) |
| } } } |
| |
| /// The type of the value produced by |
| /// [`rusty_fork_id!`](macro.rusty_fork_id.html). |
| #[derive(Clone, Hash, PartialEq, Debug)] |
| pub struct RustyForkId(::std::any::TypeId); |
| impl RustyForkId { |
| #[allow(missing_docs)] |
| #[doc(hidden)] |
| pub fn of(id: ::std::any::TypeId) -> Self { |
| RustyForkId(id) |
| } |
| } |
| |
| #[cfg(test)] |
| mod test { |
| #[test] |
| fn ids_are_actually_distinct() { |
| assert_ne!(rusty_fork_id!(), rusty_fork_id!()); |
| } |
| } |
