git: 63ffcf6971a3 - main - libutil++: Add freebsd::nvlist_up wrapper class for std::unique_ptr<>

The branch main has been updated by jhb:

URL: https://cgit.FreeBSD.org/src/commit/?id=63ffcf6971a36e00efc138c3261b499aa48e102f

commit 63ffcf6971a36e00efc138c3261b499aa48e102f
Author:     John Baldwin <jhb@FreeBSD.org>
AuthorDate: 2025-08-04 19:38:07 +0000
Commit:     John Baldwin <jhb@FreeBSD.org>
CommitDate: 2025-08-04 19:38:07 +0000

    libutil++: Add freebsd::nvlist_up wrapper class for std::unique_ptr<>
    
    This class uses a custom deleter that calls nvlist_destroy().
    
    Sponsored by:   Chelsio Communications
    Pull Request:   https://github.com/freebsd/freebsd-src/pull/1794
---
 lib/libutil++/Makefile             |  1 +
 lib/libutil++/freebsd::nvlist_up.3 | 37 +++++++++++++++++++++++++++++++++++++
 lib/libutil++/libutil++.hh         | 14 ++++++++++++++
 3 files changed, 52 insertions(+)

diff --git a/lib/libutil++/Makefile b/lib/libutil++/Makefile
index e64c9fe6cb75..3389e7e21b11 100644
--- a/lib/libutil++/Makefile
+++ b/lib/libutil++/Makefile
@@ -8,6 +8,7 @@ MAN+=	freebsd::FILE_up.3 \
 	freebsd::addrinfo_up.3 \
 	freebsd::fd_up.3 \
 	freebsd::malloc_up.3 \
+	freebsd::nvlist_up.3 \
 	freebsd::stringf.3
 
 .include <src.opts.mk>
diff --git a/lib/libutil++/freebsd::nvlist_up.3 b/lib/libutil++/freebsd::nvlist_up.3
new file mode 100644
index 000000000000..43f76cf3ead3
--- /dev/null
+++ b/lib/libutil++/freebsd::nvlist_up.3
@@ -0,0 +1,37 @@
+.\"
+.\" SPDX-License-Identifier: BSD-2-Clause
+.\"
+.\" Copyright (c) 2025 Chelsio Communications, Inc.
+.\" Written by: John Baldwin <jhb@FreeBSD.org>
+.\"
+.Dd July 31, 2025
+.Dt FREEBSD::NVLIST_UP 3
+.Os
+.Sh NAME
+.Nm freebsd::nvlist_up
+.Nd std::unique_ptr specialization for name/value pairs
+.Sh LIBRARY
+.Lb libutil++
+.Sh SYNOPSIS
+.In libutil++.hh
+.Ft using nvlist_up = std::unique_ptr<nvlist, nvlist_deleter>;
+.Sh DESCRIPTION
+This class is a specialization of
+.Vt std::unique_ptr
+for
+.Vt nvlist_t
+objects.
+When an
+.Vt nvlist_t
+object managed by an instance of this class is disposed,
+.Xr nvlist_destroy 3
+is invoked to dispose of the object.
+.Sh EXAMPLES
+.Bd -literal -offset indent
+freebsd::nvlist_up nvl(nvlist_create(0));
+nvlist_add_number(nvl.get(), "answer", 42);
+nvlist_add_bool(nvl.get(), "valid", true);
+// `nvl' is implicitly destroyed
+.Ed
+.Sh SEE ALSO
+.Xr nvlist_destroy 3
diff --git a/lib/libutil++/libutil++.hh b/lib/libutil++/libutil++.hh
index 616bbecd8a12..121633c4deea 100644
--- a/lib/libutil++/libutil++.hh
+++ b/lib/libutil++/libutil++.hh
@@ -8,6 +8,7 @@
 #ifndef __LIBUTILPP_HH__
 #define	__LIBUTILPP_HH__
 
+#include <sys/nv.h>
 #include <netdb.h>
 #include <unistd.h>
 
@@ -131,6 +132,19 @@ namespace freebsd {
 	template <class T>
 	using malloc_up = std::unique_ptr<T, free_deleter<T>>;
 
+	/*
+	 * nvlist_up is a std::unique_ptr<> for nvlist_t objects which
+	 * uses nvlist_destroy() to destroy the wrapped pointer.
+	 */
+	struct nvlist_deleter {
+		void operator() (nvlist_t *nvl) const
+		{
+			nvlist_destroy(nvl);
+		}
+	};
+
+	using nvlist_up = std::unique_ptr<nvlist_t, nvlist_deleter>;
+
 	/*
 	 * Returns a std::string containing the same output as
 	 * sprintf().  Throws std::bad_alloc if an error occurs.