From e2270ecd3979ac83ac8d98ad048a25fb9d49aef1 Mon Sep 17 00:00:00 2001
From: Niklas Fiekas <niklas.fiekas@backscattering.de>
Date: Wed, 22 Jan 2020 12:51:49 +0100
Subject: [PATCH] Document from_bits_unchecked unsafety (#200)

---
 src/lib.rs | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/src/lib.rs b/src/lib.rs
index b8568ad7..55daa5ea 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -637,6 +637,15 @@ macro_rules! __impl_bitflags {
             __fn_bitflags! {
                 /// Convert from underlying bit representation, preserving all
                 /// bits (even those not corresponding to a defined flag).
+                ///
+                /// # Safety
+                ///
+                /// The caller of the `bitflags!` macro can chose to allow or
+                /// disallow extra bits for their bitflags type.
+                ///
+                /// The caller of `from_bits_unchecked()` has to ensure that
+                /// all bits correspond to a defined flag or that extra bits
+                /// are valid for this bitflags type.
                 #[inline]
                 pub const unsafe fn from_bits_unchecked(bits: $T) -> $BitFlags {
                     $BitFlags { bits }