1 files changed, 50 insertions, 0 deletions
diff --git a/third_party/rust/time/src/parsing/shim.rs b/third_party/rust/time/src/parsing/shim.rs
new file mode 100644
index 0000000000..00aaf4852b
--- /dev/null
+++ b/third_party/rust/time/src/parsing/shim.rs
@@ -0,0 +1,50 @@
+//! Extension traits for things either not implemented or not yet stable in the MSRV.
+
+/// Equivalent of `foo.parse()` for slices.
+pub(crate) trait IntegerParseBytes<T> {
+    #[allow(clippy::missing_docs_in_private_items)]
+    fn parse_bytes(&self) -> Option<T>;
+}
+
+impl<T: Integer> IntegerParseBytes<T> for [u8] {
+    fn parse_bytes(&self) -> Option<T> {
+        T::parse_bytes(self)
+    }
+}
+
+/// Marker trait for all integer types, including `NonZero*`
+pub(crate) trait Integer: Sized {
+    #[allow(clippy::missing_docs_in_private_items)]
+    fn parse_bytes(src: &[u8]) -> Option<Self>;
+}
+
+/// Parse the given types from bytes.
+macro_rules! impl_parse_bytes {
+    ($($t:ty)*) => ($(
+        impl Integer for $t {
+            #[allow(trivial_numeric_casts)]
+            fn parse_bytes(src: &[u8]) -> Option<Self> {
+                src.iter().try_fold::<Self, _, _>(0, |result, c| {
+                    result.checked_mul(10)?.checked_add((c - b'0') as Self)
+                })
+            }
+        }
+    )*)
+}
+impl_parse_bytes! { u8 u16 u32 }
+
+/// Parse the given types from bytes.
+macro_rules! impl_parse_bytes_nonzero {
+    ($($t:ty)*) => {$(
+        impl Integer for $t {
+            fn parse_bytes(src: &[u8]) -> Option<Self> {
+                Self::new(src.parse_bytes()?)
+            }
+        }
+    )*}
+}
+
+impl_parse_bytes_nonzero! {
+    core::num::NonZeroU8
+    core::num::NonZeroU16
+}