From: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Date: Sat, 4 Feb 2023 00:24:54 +0000 (-0500)
Subject: common: Add a default nullptr argument to make_unique_wrapper
X-Git-Url: https://git.lttng.org./?a=commitdiff_plain;h=799462ffd674d972289608c72b3f271a5839677a;p=lttng-tools.git

common: Add a default nullptr argument to make_unique_wrapper

When wrapping C libraries that return unmanaged pointers,
lttng::make_unique_wrapper makes it easier to locally "wrap" returned
pointers.

  auto val = lttng::make_unique_ptr<struct foo *,
                                    lttng::free>(some_func());

However, in its current form, a nullptr must be passed to define an
alias:

  using my_type_uptr =
    decltype(lttng::make_unique_wrapper<lttng_session,
                                        lttng::free>(nullptr));

Adding a default nullptr argument cuts down a bit of boiler plate.

Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: I9d05d8162d28cc156b1e9ec6fe623f1cc02e9c8e
---

diff --git a/src/common/make-unique-wrapper.hpp b/src/common/make-unique-wrapper.hpp
index e49e5ced7..ebec2ca45 100644
--- a/src/common/make-unique-wrapper.hpp
+++ b/src/common/make-unique-wrapper.hpp
@@ -70,7 +70,7 @@ void free(Type *ptr)
 template <typename WrappedType, void (*DeleterFunc)(WrappedType *)>
 std::unique_ptr<WrappedType,
 		typename memory::create_deleter_class<WrappedType, DeleterFunc>::deleter>
-make_unique_wrapper(WrappedType *instance)
+make_unique_wrapper(WrappedType *instance = nullptr)
 {
 	const memory::create_deleter_class<WrappedType, DeleterFunc> unique_deleter;