Fix type storage copy and move assignment function helper

Previously, in the case both the lhs and rhs optionals were present, the copy/move assignments were erroneously destroying the lhs object.

lib/include/srsran/adt/detail/type_storage.h

@@ -70,11 +70,9 @@ void copy_if_present_helper(type_storage<T, MinSize, AlignSize>&       lhs,
 {
   if (lhs_present and rhs_present) {
     lhs.get() = rhs.get();
-  }
-  if (lhs_present) {
+  } else if (lhs_present) {
     lhs.destroy();
-  }
-  if (rhs_present) {
+  } else if (rhs_present) {
     lhs.copy_ctor(rhs);
   }
 }
@@ -87,11 +85,9 @@ void move_if_present_helper(type_storage<T, MinSize, AlignSize>& lhs,
 {
   if (lhs_present and rhs_present) {
     lhs.move_assign(std::move(rhs));
-  }
-  if (lhs_present) {
+  } else if (lhs_present) {
     lhs.destroy();
-  }
-  if (rhs_present) {
+  } else if (rhs_present) {
     lhs.move_ctor(std::move(rhs));
   }
 }

lib/test/adt/optional_test.cc

@@ -29,7 +29,26 @@ void test_optional_int()
   TESTASSERT(opt == opt2);
 }
 
+struct C {
+  std::unique_ptr<int> val;
+
+  C(int val = 0) : val(std::make_unique<int>(val)) {}
+};
+
+void test_optional_move_only()
+{
+  optional<C> a, b;
+  a.emplace(C{});
+  TESTASSERT(a.has_value());
+  TESTASSERT_EQ(0, *a.value().val);
+  TESTASSERT(not b.has_value());
+  b.emplace(C{5});
+  a = std::move(b);
+  TESTASSERT_EQ(5, *a.value().val);
+}
+
 int main()
 {
   test_optional_int();
+  test_optional_move_only();
 }