Make core::sync::atomic::Ordering #[non_exhaustive]

src/libcore/lib.rs

@@ -120,6 +120,7 @@
 #![feature(const_slice_len)]
 #![feature(const_str_as_bytes)]
 #![feature(const_str_len)]
+#![feature(non_exhaustive)]
 
 #[prelude_import]
 #[allow(unused)]

src/libcore/sync/atomic.rs

@@ -185,6 +185,7 @@ unsafe impl<T> Sync for AtomicPtr<T> {}
 /// [nomicon]: ../../../nomicon/atomics.html
 #[stable(feature = "rust1", since = "1.0.0")]
 #[derive(Copy, Clone, Debug)]
+#[non_exhaustive]
 pub enum Ordering {
     /// No ordering constraints, only atomic operations.
     ///
@@ -256,10 +257,6 @@ pub enum Ordering {
     /// [`AcqRel`]: https://llvm.org/docs/Atomics.html#acquirerelease
     #[stable(feature = "rust1", since = "1.0.0")]
     SeqCst,
-    // Prevent exhaustive matching to allow for future extension
-    #[doc(hidden)]
-    #[unstable(feature = "future_atomic_orderings", issue = "0")]
-    __Nonexhaustive,
 }
 
 /// An [`AtomicBool`] initialized to `false`.
@@ -1954,7 +1951,6 @@ fn strongest_failure_ordering(order: Ordering) -> Ordering {
         SeqCst => SeqCst,
         Acquire => Acquire,
         AcqRel => Acquire,
-        __Nonexhaustive => __Nonexhaustive,
     }
 }
 
@@ -1966,7 +1962,6 @@ unsafe fn atomic_store<T>(dst: *mut T, val: T, order: Ordering) {
         SeqCst => intrinsics::atomic_store(dst, val),
         Acquire => panic!("there is no such thing as an acquire store"),
         AcqRel => panic!("there is no such thing as an acquire/release store"),
-        __Nonexhaustive => panic!("invalid memory ordering"),
     }
 }
 
@@ -1978,7 +1973,6 @@ unsafe fn atomic_load<T>(dst: *const T, order: Ordering) -> T {
         SeqCst => intrinsics::atomic_load(dst),
         Release => panic!("there is no such thing as a release load"),
         AcqRel => panic!("there is no such thing as an acquire/release load"),
-        __Nonexhaustive => panic!("invalid memory ordering"),
     }
 }
 
@@ -1991,7 +1985,6 @@ unsafe fn atomic_swap<T>(dst: *mut T, val: T, order: Ordering) -> T {
         AcqRel => intrinsics::atomic_xchg_acqrel(dst, val),
         Relaxed => intrinsics::atomic_xchg_relaxed(dst, val),
         SeqCst => intrinsics::atomic_xchg(dst, val),
-        __Nonexhaustive => panic!("invalid memory ordering"),
     }
 }
 
@@ -2004,7 +1997,6 @@ unsafe fn atomic_add<T>(dst: *mut T, val: T, order: Ordering) -> T {
         AcqRel => intrinsics::atomic_xadd_acqrel(dst, val),
         Relaxed => intrinsics::atomic_xadd_relaxed(dst, val),
         SeqCst => intrinsics::atomic_xadd(dst, val),
-        __Nonexhaustive => panic!("invalid memory ordering"),
     }
 }
 
@@ -2017,7 +2009,6 @@ unsafe fn atomic_sub<T>(dst: *mut T, val: T, order: Ordering) -> T {
         AcqRel => intrinsics::atomic_xsub_acqrel(dst, val),
         Relaxed => intrinsics::atomic_xsub_relaxed(dst, val),
         SeqCst => intrinsics::atomic_xsub(dst, val),
-        __Nonexhaustive => panic!("invalid memory ordering"),
     }
 }
 
@@ -2039,8 +2030,6 @@ unsafe fn atomic_compare_exchange<T>(dst: *mut T,
         (AcqRel, Relaxed) => intrinsics::atomic_cxchg_acqrel_failrelaxed(dst, old, new),
         (SeqCst, Relaxed) => intrinsics::atomic_cxchg_failrelaxed(dst, old, new),
         (SeqCst, Acquire) => intrinsics::atomic_cxchg_failacq(dst, old, new),
-        (__Nonexhaustive, _) => panic!("invalid memory ordering"),
-        (_, __Nonexhaustive) => panic!("invalid memory ordering"),
         (_, AcqRel) => panic!("there is no such thing as an acquire/release failure ordering"),
         (_, Release) => panic!("there is no such thing as a release failure ordering"),
         _ => panic!("a failure ordering can't be stronger than a success ordering"),
@@ -2065,8 +2054,6 @@ unsafe fn atomic_compare_exchange_weak<T>(dst: *mut T,
         (AcqRel, Relaxed) => intrinsics::atomic_cxchgweak_acqrel_failrelaxed(dst, old, new),
         (SeqCst, Relaxed) => intrinsics::atomic_cxchgweak_failrelaxed(dst, old, new),
         (SeqCst, Acquire) => intrinsics::atomic_cxchgweak_failacq(dst, old, new),
-        (__Nonexhaustive, _) => panic!("invalid memory ordering"),
-        (_, __Nonexhaustive) => panic!("invalid memory ordering"),
         (_, AcqRel) => panic!("there is no such thing as an acquire/release failure ordering"),
         (_, Release) => panic!("there is no such thing as a release failure ordering"),
         _ => panic!("a failure ordering can't be stronger than a success ordering"),
@@ -2082,7 +2069,6 @@ unsafe fn atomic_and<T>(dst: *mut T, val: T, order: Ordering) -> T {
         AcqRel => intrinsics::atomic_and_acqrel(dst, val),
         Relaxed => intrinsics::atomic_and_relaxed(dst, val),
         SeqCst => intrinsics::atomic_and(dst, val),
-        __Nonexhaustive => panic!("invalid memory ordering"),
     }
 }
 
@@ -2094,7 +2080,6 @@ unsafe fn atomic_nand<T>(dst: *mut T, val: T, order: Ordering) -> T {
         AcqRel => intrinsics::atomic_nand_acqrel(dst, val),
         Relaxed => intrinsics::atomic_nand_relaxed(dst, val),
         SeqCst => intrinsics::atomic_nand(dst, val),
-        __Nonexhaustive => panic!("invalid memory ordering"),
     }
 }
 
@@ -2106,7 +2091,6 @@ unsafe fn atomic_or<T>(dst: *mut T, val: T, order: Ordering) -> T {
         AcqRel => intrinsics::atomic_or_acqrel(dst, val),
         Relaxed => intrinsics::atomic_or_relaxed(dst, val),
         SeqCst => intrinsics::atomic_or(dst, val),
-        __Nonexhaustive => panic!("invalid memory ordering"),
     }
 }
 
@@ -2118,7 +2102,6 @@ unsafe fn atomic_xor<T>(dst: *mut T, val: T, order: Ordering) -> T {
         AcqRel => intrinsics::atomic_xor_acqrel(dst, val),
         Relaxed => intrinsics::atomic_xor_relaxed(dst, val),
         SeqCst => intrinsics::atomic_xor(dst, val),
-        __Nonexhaustive => panic!("invalid memory ordering"),
     }
 }
 
@@ -2131,7 +2114,6 @@ unsafe fn atomic_max<T>(dst: *mut T, val: T, order: Ordering) -> T {
         AcqRel => intrinsics::atomic_max_acqrel(dst, val),
         Relaxed => intrinsics::atomic_max_relaxed(dst, val),
         SeqCst => intrinsics::atomic_max(dst, val),
-        __Nonexhaustive => panic!("invalid memory ordering"),
     }
 }
 
@@ -2144,7 +2126,6 @@ unsafe fn atomic_min<T>(dst: *mut T, val: T, order: Ordering) -> T {
         AcqRel => intrinsics::atomic_min_acqrel(dst, val),
         Relaxed => intrinsics::atomic_min_relaxed(dst, val),
         SeqCst => intrinsics::atomic_min(dst, val),
-        __Nonexhaustive => panic!("invalid memory ordering"),
     }
 }
 
@@ -2157,7 +2138,6 @@ unsafe fn atomic_umax<T>(dst: *mut T, val: T, order: Ordering) -> T {
         AcqRel => intrinsics::atomic_umax_acqrel(dst, val),
         Relaxed => intrinsics::atomic_umax_relaxed(dst, val),
         SeqCst => intrinsics::atomic_umax(dst, val),
-        __Nonexhaustive => panic!("invalid memory ordering"),
     }
 }
 
@@ -2170,7 +2150,6 @@ unsafe fn atomic_umin<T>(dst: *mut T, val: T, order: Ordering) -> T {
         AcqRel => intrinsics::atomic_umin_acqrel(dst, val),
         Relaxed => intrinsics::atomic_umin_relaxed(dst, val),
         SeqCst => intrinsics::atomic_umin(dst, val),
-        __Nonexhaustive => panic!("invalid memory ordering"),
     }
 }
 
@@ -2260,7 +2239,6 @@ pub fn fence(order: Ordering) {
             AcqRel => intrinsics::atomic_fence_acqrel(),
             SeqCst => intrinsics::atomic_fence(),
             Relaxed => panic!("there is no such thing as a relaxed fence"),
-            __Nonexhaustive => panic!("invalid memory ordering"),
         }
     }
 }
@@ -2350,7 +2328,6 @@ pub fn compiler_fence(order: Ordering) {
             AcqRel => intrinsics::atomic_singlethreadfence_acqrel(),
             SeqCst => intrinsics::atomic_singlethreadfence(),
             Relaxed => panic!("there is no such thing as a relaxed compiler fence"),
-            __Nonexhaustive => panic!("invalid memory ordering"),
         }
     }
 }