Use <[T]>::split_at_checked instead of two separate get calls

.github/workflows/ci.yml

@@ -67,7 +67,7 @@ jobs:
           - os: ubuntu-latest
             # MSRV. Not considered breaking when this has to be bumped.
             # But update `rust-version` in `Cargo.toml`
-            rust: 1.77.0
+            rust: 1.80.0
     runs-on: ${{ matrix.os }}
     steps:
       - uses: actions/checkout@v4

Cargo.toml

@@ -6,7 +6,7 @@ license = "MIT OR Apache-2.0"
 description = "Tunnel UDP traffic inside a TCP stream. Each datagram is prefixed with a 16 bit unsigned integer containing the length"
 repository = "https://github.com/mullvad/udp-over-tcp"
 edition = "2021"
-rust-version = "1.77.0"
+rust-version = "1.80.0"
 publish = false
 
 [[bin]]

src/forward_traffic.rs

@@ -127,12 +127,7 @@ fn split_first_datagram(buffer: &[u8]) -> Option<(&[u8], &[u8])> {
     let (header, tail) = buffer.split_first_chunk::<HEADER_LEN>()?;
     let datagram_len = usize::from(u16::from_be_bytes(*header));
 
-    // TODO: These two get calls (and thus double bounds check) can be replaced with
-    // `split_at_checked` when stabilized: https://github.com/rust-lang/rust/issues/119128
-    let datagram_data = tail.get(..datagram_len)?;
-    let tail = tail.get(datagram_len..)?;
-
-    Some((datagram_data, tail))
+    tail.split_at_checked(datagram_len)
 }
 
 /// Reads datagrams from `udp_in` and writes them (with the 16 bit header containing the length)