Fix weird error?

Author: matt-cornell

cobalt-ast/src/context.rs

@@ -372,12 +372,14 @@ impl Serialize for CompCtx<'_, '_> {
         S: Serializer,
     {
         use ser::*;
-        #[allow(clippy::unnecessary_cast)]
         SERIALIZATION_CONTEXT.with(|c| {
-            if let Some(ptr) = c.replace(Some(ContextPointer::new(
-                self as *const CompCtx<'_, '_> as *const CompCtx<'static, 'static>, // this intermediate cast is necessary
-            ))) {
-                if *ptr != (self as *const CompCtx<'_, '_> as *const CompCtx<'static, 'static>) {
+            let p = unsafe {
+                std::mem::transmute::<*const CompCtx<'_, '_>, *const CompCtx<'static, 'static>>(
+                    self as _,
+                )
+            };
+            if let Some(ptr) = c.replace(Some(ContextPointer::new(p))) {
+                if *ptr != p {
                     panic!("serialization context is already in use with an address of {ptr:#?}");
                 }
             }
@@ -409,12 +411,14 @@ impl<'de> DeserializeSeed<'de> for &CompCtx<'_, '_> {
         D: Deserializer<'de>,
     {
         use de::*;
-        #[allow(clippy::unnecessary_cast)]
         SERIALIZATION_CONTEXT.with(|c| {
-            if let Some(ptr) = c.replace(Some(ContextPointer::new(
-                self as *const CompCtx<'_, '_> as *const CompCtx<'static, 'static>, // this intermediate cast is necessary
-            ))) {
-                if *ptr != (self as *const CompCtx<'_, '_> as *const CompCtx<'static, 'static>) {
+            let p = unsafe {
+                std::mem::transmute::<*const CompCtx<'_, '_>, *const CompCtx<'static, 'static>>(
+                    self as _,
+                )
+            };
+            if let Some(ptr) = c.replace(Some(ContextPointer::new(p))) {
+                if *ptr != p {
                     panic!("serialization context is already in use with an address of {ptr:#?}");
                 }
             }