From 6c818bb37a55ca44cb6241a29a836332191b476c Mon Sep 17 00:00:00 2001
From: Max Kellermann <max@musicpd.org>
Date: Tue, 13 Dec 2016 20:55:48 +0100
Subject: [PATCH] AudioFormat: add method WithMask(), shortcut for ApplyMask()

---
 src/AudioFormat.hxx            | 7 +++++++
 src/decoder/DecoderControl.cxx | 3 +--
 src/output/OutputThread.cxx    | 3 +--
 test/run_convert.cxx           | 4 ++--
 4 files changed, 11 insertions(+), 6 deletions(-)

diff --git a/src/AudioFormat.hxx b/src/AudioFormat.hxx
index 891056338..37d806af1 100644
--- a/src/AudioFormat.hxx
+++ b/src/AudioFormat.hxx
@@ -159,6 +159,13 @@ struct AudioFormat {
 
 	void ApplyMask(AudioFormat mask);
 
+	gcc_pure
+	AudioFormat WithMask(AudioFormat mask) const {
+		AudioFormat result = *this;
+		result.ApplyMask(mask);
+		return result;
+	}
+
 	/**
 	 * Returns the size of each (mono) sample in bytes.
 	 */
diff --git a/src/decoder/DecoderControl.cxx b/src/decoder/DecoderControl.cxx
index f2915a3f7..259d51a1f 100644
--- a/src/decoder/DecoderControl.cxx
+++ b/src/decoder/DecoderControl.cxx
@@ -64,8 +64,7 @@ DecoderControl::SetReady(const AudioFormat audio_format,
 	assert(audio_format.IsValid());
 
 	in_audio_format = audio_format;
-	out_audio_format = audio_format;
-	out_audio_format.ApplyMask(configured_audio_format);
+	out_audio_format = audio_format.WithMask(configured_audio_format);
 
 	seekable = _seekable;
 	total_time = _duration;
diff --git a/src/output/OutputThread.cxx b/src/output/OutputThread.cxx
index 513d6babb..bce998949 100644
--- a/src/output/OutputThread.cxx
+++ b/src/output/OutputThread.cxx
@@ -159,8 +159,7 @@ AudioOutput::Open()
 
 	assert(filter_audio_format.IsValid());
 
-	out_audio_format = filter_audio_format;
-	out_audio_format.ApplyMask(config_audio_format);
+	out_audio_format = filter_audio_format.WithMask(config_audio_format);
 
 	mutex.unlock();
 
diff --git a/test/run_convert.cxx b/test/run_convert.cxx
index 13d69a242..f4a3f1adc 100644
--- a/test/run_convert.cxx
+++ b/test/run_convert.cxx
@@ -49,8 +49,8 @@ try {
 	const auto in_audio_format = ParseAudioFormat(argv[1], false);
 	const auto out_audio_format_mask = ParseAudioFormat(argv[2], false);
 
-	auto out_audio_format = in_audio_format;
-	out_audio_format.ApplyMask(out_audio_format_mask);
+	const auto out_audio_format =
+		in_audio_format.WithMask(out_audio_format_mask);
 
 	const size_t in_frame_size = in_audio_format.GetFrameSize();