From e568ad9c035f41bcd48f29649b5c1281e3bf7ea3 Mon Sep 17 00:00:00 2001
From: diekmann <diekmann@net.in.tum.de>
Date: Sun, 26 Mar 2017 17:06:07 +0200
Subject: [PATCH] Self should not be mutated (pull request 564)

---
 CHANGELOG.md      | 2 ++
 src/sys/select.rs | 2 +-
 2 files changed, 3 insertions(+), 1 deletion(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 3db0555213..dc2deee593 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -18,6 +18,8 @@ This project adheres to [Semantic Versioning](http://semver.org/).
 - Removed `revents` argument from `PollFd::new()` as it's an output argument and
   will be overwritten regardless of value.
   ([#542](https://github.com/nix-rust/nix/pull/542))
+- Changed type signature of `sys::select::FdSet::contains` to make `self`
+  immutable ([#564](https://github.com/nix-rust/nix/pull/564))
 
 ### Fixed
 - Fixed multiple issues compiling under different archetectures and OSes.
diff --git a/src/sys/select.rs b/src/sys/select.rs
index 1d9a76c1d4..eae191b6e4 100644
--- a/src/sys/select.rs
+++ b/src/sys/select.rs
@@ -43,7 +43,7 @@ impl FdSet {
         self.bits[fd / BITS] &= !(1 << (fd % BITS));
     }
 
-    pub fn contains(&mut self, fd: RawFd) -> bool {
+    pub fn contains(&self, fd: RawFd) -> bool {
         let fd = fd as usize;
         self.bits[fd / BITS] & (1 << (fd % BITS)) > 0
     }