Merge pull request eclipse-zenoh#303 from DenisBiryukov91/qol/guarded…

…_transmute_with_deref

implementation_guarded_transmute with from and deref

src/attachment.rs

@@ -176,7 +176,7 @@ pub struct z_owned_bytes_map_t {
     _1: [usize; 4],
 }
 
-impl_guarded_transmute!(
+impl_guarded_transmute!(noderefs
     Option<HashMap<Cow<'static, [u8]>, Cow<'static, [u8]>>>,
     z_owned_bytes_map_t
 );

src/commons.rs

@@ -198,20 +198,6 @@ pub extern "C" fn zc_payload_null() -> zc_owned_payload_t {
 pub struct z_qos_t(u8);
 
 impl_guarded_transmute!(QoS, z_qos_t);
-impl_guarded_transmute!(z_qos_t, QoS);
-
-impl From<QoS> for z_qos_t {
-    fn from(qos: QoS) -> Self {
-        qos.transmute()
-    }
-}
-
-impl From<z_qos_t> for QoS {
-    fn from(qos: z_qos_t) -> QoS {
-        qos.transmute()
-    }
-}
-
 /// Returns message priority.
 #[no_mangle]
 pub extern "C" fn z_qos_get_priority(qos: z_qos_t) -> z_priority_t {

src/config.rs

@@ -15,7 +15,7 @@ use libc::{c_char, c_uint};
 use std::ffi::CStr;
 use zenoh::config::{Config, ValidatedMap, WhatAmI};
 
-use crate::{impl_guarded_transmute, z_owned_str_t, z_str_null, GuardedTransmute};
+use crate::{impl_guarded_transmute, z_owned_str_t, z_str_null};
 
 #[no_mangle]
 pub static Z_ROUTER: c_uint = WhatAmI::Router as c_uint;
@@ -76,11 +76,6 @@ pub struct z_config_t(*const z_owned_config_t);
 pub struct z_owned_config_t(*mut ());
 impl_guarded_transmute!(Option<Box<Config>>, z_owned_config_t);
 
-impl From<Option<Box<Config>>> for z_owned_config_t {
-    fn from(v: Option<Box<Config>>) -> Self {
-        v.transmute()
-    }
-}
 /// Returns a :c:type:`z_config_t` loaned from `s`.
 #[no_mangle]
 pub extern "C" fn z_config_loan(s: &z_owned_config_t) -> z_config_t {

src/get.rs

@@ -56,7 +56,7 @@ pub struct z_owned_reply_t([u64; 30]);
 #[repr(C, align(8))]
 pub struct z_owned_reply_t([u64; 19]);
 
-impl_guarded_transmute!(ReplyInner, z_owned_reply_t);
+impl_guarded_transmute!(noderefs ReplyInner, z_owned_reply_t);
 
 impl From<ReplyInner> for z_owned_reply_t {
     fn from(mut val: ReplyInner) -> Self {

src/keyexpr.rs

@@ -63,27 +63,11 @@ pub struct z_owned_keyexpr_t([u32; 5]);
 
 impl_guarded_transmute!(Option<KeyExpr<'static>>, z_owned_keyexpr_t);
 
-impl From<Option<KeyExpr<'static>>> for z_owned_keyexpr_t {
-    fn from(val: Option<KeyExpr<'static>>) -> Self {
-        val.transmute()
-    }
-}
 impl From<KeyExpr<'static>> for z_owned_keyexpr_t {
     fn from(val: KeyExpr<'static>) -> Self {
         Some(val).into()
     }
 }
-impl Deref for z_owned_keyexpr_t {
-    type Target = Option<KeyExpr<'static>>;
-    fn deref(&self) -> &Self::Target {
-        unsafe { std::mem::transmute(self) }
-    }
-}
-impl DerefMut for z_owned_keyexpr_t {
-    fn deref_mut(&mut self) -> &mut Self::Target {
-        unsafe { std::mem::transmute(self) }
-    }
-}
 impl z_owned_keyexpr_t {
     pub fn null() -> Self {
         None::<KeyExpr>.into()
@@ -183,8 +167,8 @@ pub struct z_keyexpr_t([u64; 4]);
 #[repr(C, align(4))]
 pub struct z_keyexpr_t([u32; 5]);
 
-impl_guarded_transmute!(Option<KeyExpr<'_>>, z_keyexpr_t);
-impl_guarded_transmute!(z_keyexpr_t, z_owned_keyexpr_t);
+impl_guarded_transmute!(noderefs Option<KeyExpr<'_>>, z_keyexpr_t);
+impl_guarded_transmute!(noderefs z_keyexpr_t, z_owned_keyexpr_t);
 
 impl<'a> From<KeyExpr<'a>> for z_keyexpr_t {
     fn from(val: KeyExpr<'a>) -> Self {

src/lib.rs

@@ -62,9 +62,37 @@ trait GuardedTransmute<D> {
     fn transmute(self) -> D;
 }
 
+/// For internal use only.
+///
+/// This macro is used to establish the equivalence between a Rust type (first parameter) and a C layout (second parameter).
+///
+/// It automatically implements `From`, `Deref` and `DerefMut` to make writing code around these equivalent types.
+///
+/// Because carrying around the proper semantics of lifetimes is hard, this macro fails to produce working code when lifetimes are
+/// present in either parameter. You may then call it with the `noderefs` prefix to avoid the offending implementations being defined.
 #[macro_export]
 macro_rules! impl_guarded_transmute {
     ($src_type:ty, $dst_type:ty) => {
+        impl_guarded_transmute!(noderefs $src_type, $dst_type);
+        impl From<$src_type> for $dst_type {
+            fn from(value: $src_type) -> $dst_type {
+                unsafe { core::mem::transmute(value) }
+            }
+        }
+        impl core::ops::Deref for $dst_type {
+            type Target = $src_type;
+            fn deref(&self) -> &$src_type {
+                unsafe { core::mem::transmute(self) }
+            }
+        }
+        impl core::ops::DerefMut for $dst_type {
+            fn deref_mut(&mut self) -> &mut $src_type {
+                unsafe { core::mem::transmute(self) }
+            }
+        }
+
+    };
+    (noderefs $src_type:ty, $dst_type:ty) => {
         const _: () = {
             let src = std::mem::align_of::<$src_type>();
             let dst = std::mem::align_of::<$dst_type>();
@@ -81,12 +109,36 @@ macro_rules! impl_guarded_transmute {
                 });
             }
         };
-        impl $crate::GuardedTransmute<$dst_type> for $src_type {
+        impl  $crate::GuardedTransmute<$dst_type> for $src_type {
             fn transmute(self) -> $dst_type {
                 unsafe { std::mem::transmute::<$src_type, $dst_type>(self) }
             }
         }
     };
+    ($src_type:ty, $dst_type:ty, $($gen: tt)*) => {
+        impl<$($gen)*>  $crate::GuardedTransmute<$dst_type> for $src_type {
+            fn transmute(self) -> $dst_type {
+                unsafe { std::mem::transmute::<$src_type, $dst_type>(self) }
+            }
+        }
+        impl<$($gen)*> From<$src_type> for $dst_type {
+            fn from(value: $src_type) -> $dst_type {
+                unsafe { core::mem::transmute(value) }
+            }
+        }
+        impl<$($gen)*> core::ops::Deref for $dst_type {
+            type Target = $src_type;
+            fn deref(&self) -> &$src_type {
+                unsafe { core::mem::transmute(self) }
+            }
+        }
+        impl<$($gen)*> core::ops::DerefMut for $dst_type {
+            fn deref_mut(&mut self) -> &mut $src_type {
+                unsafe { core::mem::transmute(self) }
+            }
+        }
+
+    };
 }
 
 pub(crate) const LOG_INVALID_SESSION: &str = "Invalid session";

src/platform/synchronization.rs

@@ -22,8 +22,8 @@ pub struct ZMutexPtr {
 #[derive(Clone, Copy)]
 pub struct z_mutex_t(usize);
 
-impl_guarded_transmute!(z_mutex_t, ZMutexPtr);
-impl_guarded_transmute!(ZMutexPtr, z_mutex_t);
+impl_guarded_transmute!(noderefs z_mutex_t, ZMutexPtr);
+impl_guarded_transmute!(noderefs ZMutexPtr, z_mutex_t);
 
 // using the same error codes as in GNU pthreads, but with negative sign
 // due to convention to return negative values on error
@@ -141,8 +141,8 @@ struct ZCondvarPtr {
 #[derive(Clone, Copy)]
 pub struct z_condvar_t(usize);
 
-impl_guarded_transmute!(z_condvar_t, ZCondvarPtr);
-impl_guarded_transmute!(ZCondvarPtr, z_condvar_t);
+impl_guarded_transmute!(noderefs z_condvar_t, ZCondvarPtr);
+impl_guarded_transmute!(noderefs ZCondvarPtr, z_condvar_t);
 
 #[no_mangle]
 #[allow(clippy::missing_safety_doc)]
@@ -233,8 +233,8 @@ pub struct z_task_t(usize);
 #[derive(Clone, Copy)]
 pub struct z_task_attr_t(usize);
 
-impl_guarded_transmute!(z_task_t, ZTaskPtr);
-impl_guarded_transmute!(ZTaskPtr, z_task_t);
+impl_guarded_transmute!(noderefs z_task_t, ZTaskPtr);
+impl_guarded_transmute!(noderefs ZTaskPtr, z_task_t);
 
 struct FunArgPair {
     fun: unsafe extern "C" fn(arg: *mut c_void),

src/publication_cache.rs

@@ -20,7 +20,7 @@ use zenoh_util::core::SyncResolve;
 
 use crate::{
     impl_guarded_transmute, z_keyexpr_t, z_session_t, zcu_locality_default, zcu_locality_t,
-    GuardedTransmute, UninitializedKeyExprError,
+    UninitializedKeyExprError,
 };
 
 /// Options passed to the :c:func:`ze_declare_publication_cache` function.
@@ -70,24 +70,6 @@ pub struct ze_owned_publication_cache_t([usize; 1]);
 
 impl_guarded_transmute!(PublicationCache, ze_owned_publication_cache_t);
 
-impl From<PublicationCache> for ze_owned_publication_cache_t {
-    fn from(val: PublicationCache) -> Self {
-        val.transmute()
-    }
-}
-
-impl AsRef<PublicationCache> for ze_owned_publication_cache_t {
-    fn as_ref(&self) -> &PublicationCache {
-        unsafe { std::mem::transmute(self) }
-    }
-}
-
-impl AsMut<PublicationCache> for ze_owned_publication_cache_t {
-    fn as_mut(&mut self) -> &mut PublicationCache {
-        unsafe { std::mem::transmute(self) }
-    }
-}
-
 impl ze_owned_publication_cache_t {
     pub fn new(pub_cache: zenoh_ext::PublicationCache<'static>) -> Self {
         Some(Box::new(pub_cache)).into()
@@ -187,7 +169,7 @@ pub extern "C" fn ze_publication_cache_check(pub_cache: &ze_owned_publication_ca
 pub extern "C" fn ze_undeclare_publication_cache(
     pub_cache: &mut ze_owned_publication_cache_t,
 ) -> i8 {
-    if let Some(p) = pub_cache.as_mut().take() {
+    if let Some(p) = pub_cache.take() {
         if let Err(e) = p.close().res_sync() {
             log::error!("{}", e);
             return e.errno().get();

src/publisher.rs

@@ -75,7 +75,7 @@ pub struct z_owned_publisher_t([u64; 7]);
 #[repr(C, align(4))]
 pub struct z_owned_publisher_t([u32; 8]);
 
-impl_guarded_transmute!(Option<Publisher<'_>>, z_owned_publisher_t);
+impl_guarded_transmute!(noderefs Option<Publisher<'_>>, z_owned_publisher_t);
 
 impl<'a> From<Option<Publisher<'a>>> for z_owned_publisher_t {
     fn from(val: Option<Publisher>) -> Self {
@@ -387,7 +387,7 @@ pub extern "C" fn z_publisher_keyexpr(publisher: z_publisher_t) -> z_owned_keyex
 #[repr(C, align(8))]
 pub struct zcu_owned_matching_listener_t([u64; 4]);
 
-impl_guarded_transmute!(
+impl_guarded_transmute!(noderefs
     Option<MatchingListener<'_, ()>>,
     zcu_owned_matching_listener_t
 );

src/pull_subscriber.rs

@@ -1,4 +1,3 @@
-use crate::GuardedTransmute;
 //
 // Copyright (c) 2017, 2022 ZettaScale Technology.
 //
@@ -56,21 +55,9 @@ impl_guarded_transmute!(PullSubscriber, z_owned_pull_subscriber_t);
 #[allow(non_camel_case_types)]
 pub struct z_pull_subscriber_t<'a>(&'a z_owned_pull_subscriber_t);
 
-impl From<PullSubscriber> for z_owned_pull_subscriber_t {
-    fn from(val: PullSubscriber) -> Self {
-        val.transmute()
-    }
-}
-
-impl AsRef<PullSubscriber> for z_owned_pull_subscriber_t {
-    fn as_ref(&self) -> &PullSubscriber {
-        unsafe { std::mem::transmute(self) }
-    }
-}
-
 impl<'a> AsRef<PullSubscriber> for z_pull_subscriber_t<'a> {
     fn as_ref(&self) -> &PullSubscriber {
-        self.0.as_ref()
+        self.0
     }
 }
 

src/queryable.rs

@@ -17,8 +17,7 @@ use crate::attachment::{
 };
 use crate::{
     impl_guarded_transmute, z_bytes_t, z_closure_query_call, z_encoding_default, z_encoding_t,
-    z_keyexpr_t, z_owned_closure_query_t, z_session_t, z_value_t, GuardedTransmute,
-    LOG_INVALID_SESSION,
+    z_keyexpr_t, z_owned_closure_query_t, z_session_t, z_value_t, LOG_INVALID_SESSION,
 };
 use libc::c_void;
 use std::ops::{Deref, DerefMut};
@@ -52,22 +51,6 @@ pub struct z_owned_queryable_t([u32; 4]);
 
 impl_guarded_transmute!(Queryable, z_owned_queryable_t);
 
-impl From<Queryable> for z_owned_queryable_t {
-    fn from(val: Queryable) -> Self {
-        val.transmute()
-    }
-}
-impl AsRef<Queryable> for z_owned_queryable_t {
-    fn as_ref(&self) -> &Queryable {
-        unsafe { std::mem::transmute(self) }
-    }
-}
-impl AsMut<Queryable> for z_owned_queryable_t {
-    fn as_mut(&mut self) -> &mut Queryable {
-        unsafe { std::mem::transmute(self) }
-    }
-}
-
 impl z_owned_queryable_t {
     pub fn null() -> Self {
         None.into()
@@ -263,7 +246,7 @@ pub extern "C" fn z_declare_queryable(
 #[allow(clippy::missing_safety_doc)]
 #[no_mangle]
 pub extern "C" fn z_undeclare_queryable(qable: &mut z_owned_queryable_t) -> i8 {
-    if let Some(qable) = qable.as_mut().take() {
+    if let Some(qable) = qable.take() {
         if let Err(e) = qable.undeclare().res_sync() {
             log::error!("{}", e);
             return e.errno().get();

src/querying_subscriber.rs

@@ -25,10 +25,10 @@ use crate::{
     z_owned_closure_sample_t, z_query_consolidation_none, z_query_consolidation_t,
     z_query_target_default, z_query_target_t, z_reliability_t, z_sample_t, z_session_t,
     zcu_locality_default, zcu_locality_t, zcu_reply_keyexpr_default, zcu_reply_keyexpr_t,
-    GuardedTransmute, LOG_INVALID_SESSION,
+    LOG_INVALID_SESSION,
 };
 
-struct FetchingSubscriberWrapper {
+pub struct FetchingSubscriberWrapper {
     fetching_subscriber: zenoh_ext::FetchingSubscriber<'static, ()>,
     session: z_session_t,
 }
@@ -54,27 +54,9 @@ impl_guarded_transmute!(FetchingSubscriber, ze_owned_querying_subscriber_t);
 #[allow(non_camel_case_types)]
 pub struct ze_querying_subscriber_t<'a>(&'a ze_owned_querying_subscriber_t);
 
-impl From<FetchingSubscriber> for ze_owned_querying_subscriber_t {
-    fn from(val: FetchingSubscriber) -> Self {
-        val.transmute()
-    }
-}
-
-impl AsRef<FetchingSubscriber> for ze_owned_querying_subscriber_t {
-    fn as_ref(&self) -> &FetchingSubscriber {
-        unsafe { std::mem::transmute(self) }
-    }
-}
-
 impl<'a> AsRef<FetchingSubscriber> for ze_querying_subscriber_t<'a> {
     fn as_ref(&self) -> &FetchingSubscriber {
-        self.0.as_ref()
-    }
-}
-
-impl AsMut<FetchingSubscriber> for ze_owned_querying_subscriber_t {
-    fn as_mut(&mut self) -> &mut FetchingSubscriber {
-        unsafe { std::mem::transmute(self) }
+        self.0
     }
 }
 
@@ -276,7 +258,7 @@ pub unsafe extern "C" fn ze_querying_subscriber_get(
 #[allow(clippy::missing_safety_doc)]
 #[no_mangle]
 pub extern "C" fn ze_undeclare_querying_subscriber(sub: &mut ze_owned_querying_subscriber_t) -> i8 {
-    if let Some(s) = sub.as_mut().take() {
+    if let Some(s) = sub.take() {
         if let Err(e) = s.fetching_subscriber.close().res_sync() {
             log::warn!("{}", e);
             return e.errno().get();