member taking ownership of parameter

Question

I see two reasonable solutions to the problem of a member taking ownership of a parameter:

Foo::Foo(std::unique_ptr<int> parameter)
: member(std::move(parameter))
{
}

Bar::Bar(std::unique_ptr<int> parameter)
{
    member.swap(parameter);
}

Which of these is more idiomatic, easier to understand, easier to debug, easier to maintain etc.?

Are there additional solutions to the problem that I've missed?

Answer 1

Always favour initializer list. In addition, it covers types which can be moved but not swapped, for example, or types which may have to perform expensive operations for default construction- or indeed, types which simply cannot be default constructed.