Rollup merge of #137054 - jhpratt:phantom-variance, r=Mark-Simulacrum

Make phantom variance markers transparent

Author: matthiaskrgr

library/core/src/marker/variance.rs

@@ -136,6 +136,8 @@ phantom_lifetime! {
 /// For all `'a`, the following are guaranteed:
 /// * `size_of::<PhantomCovariantLifetime<'a>>() == 0`
 /// * `align_of::<PhantomCovariantLifetime<'a>>() == 1`
+ #[rustc_pub_transparent]
+ #[repr(transparent)]
 pubstructPhantomCovariantLifetime<'a>(PhantomCovariant<&'a ()>);
 /// Zero-sized type used to mark a lifetime as contravariant.
 ///
@@ -149,6 +151,8 @@ phantom_lifetime! {
 /// For all `'a`, the following are guaranteed:
 /// * `size_of::<PhantomContravariantLifetime<'a>>() == 0`
 /// * `align_of::<PhantomContravariantLifetime<'a>>() == 1`
+ #[rustc_pub_transparent]
+ #[repr(transparent)]
 pubstructPhantomContravariantLifetime<'a>(PhantomContravariant<&'a ()>);
 /// Zero-sized type used to mark a lifetime as invariant.
 ///
@@ -162,6 +166,8 @@ phantom_lifetime! {
 /// For all `'a`, the following are guaranteed:
 /// * `size_of::<PhantomInvariantLifetime<'a>>() == 0`
 /// * `align_of::<PhantomInvariantLifetime<'a>>() == 1`
+ #[rustc_pub_transparent]
+ #[repr(transparent)]
 pubstructPhantomInvariantLifetime<'a>(PhantomInvariant<&'a ()>);
 }
 
@@ -179,6 +185,8 @@ phantom_type! {
 /// For all `T`, the following are guaranteed:
 /// * `size_of::<PhantomCovariant<T>>() == 0`
 /// * `align_of::<PhantomCovariant<T>>() == 1`
+ #[rustc_pub_transparent]
+ #[repr(transparent)]
 pubstructPhantomCovariant<T>(PhantomData<fn() -> T>);
 /// Zero-sized type used to mark a type parameter as contravariant.
 ///
@@ -193,6 +201,8 @@ phantom_type! {
 /// For all `T`, the following are guaranteed:
 /// * `size_of::<PhantomContravariant<T>>() == 0`
 /// * `align_of::<PhantomContravariant<T>>() == 1`
+ #[rustc_pub_transparent]
+ #[repr(transparent)]
 pubstructPhantomContravariant<T>(PhantomData<fn(T)>);
 /// Zero-sized type used to mark a type parameter as invariant.
 ///
@@ -206,6 +216,8 @@ phantom_type! {
 /// For all `T`, the following are guaranteed:
 /// * `size_of::<PhantomInvariant<T>>() == 0`
 /// * `align_of::<PhantomInvariant<T>>() == 1`
+ #[rustc_pub_transparent]
+ #[repr(transparent)]
 pubstructPhantomInvariant<T>(PhantomData<fn(T) -> T>);
 }