Document from_bits_unchecked unsafety (#200)
diff --git a/src/lib.rs b/src/lib.rs
index b8568ad..55daa5e 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -637,6 +637,15 @@
__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 }
