Reexport IntErrorKind in std

src/libstd/lib.rs

@@ -268,6 +268,7 @@
 #![feature(hash_raw_entry)]
 #![feature(hashmap_internals)]
 #![feature(int_error_internals)]
+#![feature(int_error_matching)]
 #![feature(integer_atomics)]
 #![feature(lang_items)]
 #![feature(libc)]

src/libstd/num.rs

@@ -16,6 +16,12 @@ pub use core::num::{NonZeroU8, NonZeroU16, NonZeroU32, NonZeroU64, NonZeroU128,
 #[stable(feature = "signed_nonzero", since = "1.34.0")]
 pub use core::num::{NonZeroI8, NonZeroI16, NonZeroI32, NonZeroI64, NonZeroI128, NonZeroIsize};
 
+#[unstable(feature = "int_error_matching",
+           reason = "it can be useful to match errors when making error messages \
+                     for integer parsing",
+           issue = "22639")]
+pub use core::num::IntErrorKind;
+
 #[cfg(test)] use crate::fmt;
 #[cfg(test)] use crate::ops::{Add, Sub, Mul, Div, Rem};