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author | Dmitry <[email protected]> | 2020-08-14 19:32:05 +0100 |
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committer | Dmitry <[email protected]> | 2020-08-14 19:32:05 +0100 |
commit | 178c3e135a2a249692f7784712492e7884ae0c00 (patch) | |
tree | ac6b769dbf7162150caa0c1624786a4dd79ff3be /crates/proc_macro_srv/src/proc_macro/bridge/closure.rs | |
parent | 06ff8e6c760ff05f10e868b5d1f9d79e42fbb49c (diff) | |
parent | c2594daf2974dbd4ce3d9b7ec72481764abaceb5 (diff) |
Merge remote-tracking branch 'origin/master'
Diffstat (limited to 'crates/proc_macro_srv/src/proc_macro/bridge/closure.rs')
-rw-r--r-- | crates/proc_macro_srv/src/proc_macro/bridge/closure.rs | 30 |
1 files changed, 30 insertions, 0 deletions
diff --git a/crates/proc_macro_srv/src/proc_macro/bridge/closure.rs b/crates/proc_macro_srv/src/proc_macro/bridge/closure.rs new file mode 100644 index 000000000..273a97715 --- /dev/null +++ b/crates/proc_macro_srv/src/proc_macro/bridge/closure.rs | |||
@@ -0,0 +1,30 @@ | |||
1 | //! lib-proc-macro Closure type (equivalent to `&mut dyn FnMut(A) -> R`) that's `repr(C)`. | ||
2 | //! | ||
3 | //! Copy from https://github.com/rust-lang/rust/blob/6050e523bae6de61de4e060facc43dc512adaccd/src/libproc_macro/bridge/closure.rs# | ||
4 | //! augmented with removing unstable features | ||
5 | |||
6 | #[repr(C)] | ||
7 | pub struct Closure<'a, A, R> { | ||
8 | call: unsafe extern "C" fn(&mut Env, A) -> R, | ||
9 | env: &'a mut Env, | ||
10 | } | ||
11 | |||
12 | struct Env; | ||
13 | |||
14 | // impl<'a, A, R> !Sync for Closure<'a, A, R> {} | ||
15 | // impl<'a, A, R> !Send for Closure<'a, A, R> {} | ||
16 | |||
17 | impl<'a, A, R, F: FnMut(A) -> R> From<&'a mut F> for Closure<'a, A, R> { | ||
18 | fn from(f: &'a mut F) -> Self { | ||
19 | unsafe extern "C" fn call<A, R, F: FnMut(A) -> R>(env: &mut Env, arg: A) -> R { | ||
20 | (*(env as *mut _ as *mut F))(arg) | ||
21 | } | ||
22 | Closure { call: call::<A, R, F>, env: unsafe { &mut *(f as *mut _ as *mut Env) } } | ||
23 | } | ||
24 | } | ||
25 | |||
26 | impl<'a, A, R> Closure<'a, A, R> { | ||
27 | pub fn call(&mut self, arg: A) -> R { | ||
28 | unsafe { (self.call)(self.env, arg) } | ||
29 | } | ||
30 | } | ||