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>

Adds the Interface Name as an argument to the *Init functions to make it
possible to select which interface is used by upnp to detect servers.

Currently "nullptr" is passed in to let the upnp library select an
interface, as before.

Should have been removed by commit a8087dc1

Fixes https://github.com/MusicPlayerDaemon/MPD/discussions/1281

The problem occurred when there was libfmt-dev installed, but it was
too old (e.g. on Debian Buster), and Meson used the wrap fallback.
Those internal MPD libraries where the libfmt dependency was not
declared were still using the old system libfmt headers, which are not
ABI-compatible with MPD's own libfmt build.

Fixes part 2 of https://github.com/MusicPlayerDaemon/MPD/issues/1279

Fixes part 1 of https://github.com/MusicPlayerDaemon/MPD/issues/1279

emplace already calls std::pair. No need for it again.

No need to emplace when calling std::make_shared.
Signed-off-by: Rosen Penev <rosenp@gmail.com>

Found with cppcoreguidelines-special-member-functions
Signed-off-by: Rosen Penev <rosenp@gmail.com>

Found with cppcoreguidelines-special-member-functions
Signed-off-by: Rosen Penev <rosenp@gmail.com>

Shorter.
Signed-off-by: Rosen Penev <rosenp@gmail.com>

Found with cppcoreguidelines-interfaces-global-init
Signed-off-by: Rosen Penev <rosenp@gmail.com>

Hooray C++17!

Found with modernize-avoid-bind
Signed-off-by: Rosen Penev <rosenp@gmail.com>

Shorter.
Signed-off-by: Rosen Penev <rosenp@gmail.com>

This is no longer necessary with the new API.

As a side effect, the input plugin closes the SMB/CIFS connection
after closing the file.

This solves one part of
https://github.com/MusicPlayerDaemon/MPD/issues/916

Fixes use-after-free crash bug during MPD shutdown.

[[maybe_unused]] (introduced in C++17) is standard C++.

https://clang.llvm.org/docs/AttributeReference.html#maybe-unused-unused
says that this is equivalent to the GNU unused attribute.
Signed-off-by: Rosen Penev <rosenp@gmail.com>

Introduced in C++17. It replaces gcc's warn_unused_result.

Found with modernize-use-nodiscard.
Signed-off-by: Rosen Penev <rosenp@gmail.com>

Found with bugprone-move-forwarding-reference
Signed-off-by: Rosen Penev <rosenp@gmail.com>

Found with modernize-loop-convert
Signed-off-by: Rosen Penev <rosenp@gmail.com>

Fixes yet another build failure (which however only affects the 0.22
branch).

Closes https://github.com/MusicPlayerDaemon/MPD/issues/666

Just like std::condition_variable, which however has no way to specify
the std::mutex directly.