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-rw-r--r--src/libcore/intrinsics.rs18
1 files changed, 18 insertions, 0 deletions
diff --git a/src/libcore/intrinsics.rs b/src/libcore/intrinsics.rs
index 4a11fb39389..75c73130891 100644
--- a/src/libcore/intrinsics.rs
+++ b/src/libcore/intrinsics.rs
@@ -1100,6 +1100,24 @@ extern "rust-intrinsic" {
     /// Below are common applications of `transmute` which can be replaced with safer
     /// constructs.
     ///
+    /// Turning raw bytes(`&[u8]`) to `u32`, `f64`, etc.:
+    ///
+    /// ```
+    /// let raw_bytes = [0x78, 0x56, 0x34, 0x12];
+    ///
+    /// let num = unsafe {
+    ///     std::mem::transmute::<[u8; 4], u32>(raw_bytes);
+    /// };
+    ///
+    /// // use `u32::from_ne_bytes` instead
+    /// let num = u32::from_ne_bytes(raw_bytes);
+    /// // or use `u32::from_le_bytes` or `u32::from_ge_bytes` to specify the endianness
+    /// let num = u32::from_le_bytes(raw_bytes);
+    /// assert_eq!(num, 0x12345678);
+    /// let num = u32::from_be_bytes(raw_bytes);
+    /// assert_eq!(num, 0x78563412);
+    /// ```
+    ///
     /// Turning a pointer into a `usize`:
     ///
     /// ```