SonarLint reports the latter to be better:

std::scoped_lock basically provides the same feature as std::lock_guard,
but is more generic: It can lock several mutexes at the same time, with a
deadlock prevention mechanism (see {rule:cpp:S5524}). The equivalent code
to perform simultaneous locking with std::lock_guard is significantly more
complex. Therefore, it is simpler to use std::scoped_lock all the time,
even when locking only one mutex (there will be no performance impact).
Signed-off-by: Rosen Penev <rosenp@gmail.com>

Fixes crash when pausing the default partition after an output was
moved to another partition.

Closes https://github.com/MusicPlayerDaemon/MPD/issues/1147

Fixes #994 - moveoutput: new AudioOutputControl created from copyMoving an output to a partition is now done via MultipleOutputs::AddCopy(),using a new AudioOutputControl constructor. Tags and always_on settings willpersist when moving outputs between partitions.

This allows interrupting the output thread (for some plugins which
implement this method).  This way, operations can be canceled
properly, instead of waiting for some external entity.

The former was deprecated with C++14.

According to the C++11 and C++17 standards, both files are identical.
Signed-off-by: Rosen Penev <rosenp@gmail.com>

Found with readability-const-return-type
Signed-off-by: Rosen Penev <rosenp@gmail.com>

Since we switched from autotools to Meson in commit
94592c14, we don't need to include
`config.h` early to properly enable large file support.  Meson passes
the required macros on the compiler command line instead of defining
them in `config.h`.

This means we can include `config.h` at any time, whenever we want to
check its macros, and there are no ordering constraints.

With the new command, the decision to pause or close the output moves
into the output thread.

Prepare for adding another Cond attribute.

All it does is "sometimes" close the mixer, but that is also done in
the destructor.

This is implicitly done by the destructor.

Fixes shutdown memory leak.

These attributes are printed in the "outputs" response, and the new
command "outputset" allows setting new values.

No attributes are currently implemented.