Quick A: No, its usage is well defined.
Recently on SO:
In hindsight, given make_shared, would shared_ptr have a constructor that takes a raw pointer had it been introduced with C++11?
What if you don't control the allocation of the object? What if you need to use a custom deleter? What if you need list-initialization instead of parens?
None of these cases is handled by
Additionally, if you're using
make_sharedwon't free any memory until all the
weak_ptrs are destroyed as well. So even if you have a normal shared pointer where none of the above apply, it's possible that you may still prefer the raw pointer constructor.
Yet another situation would be if your type provides overloads for operator
delete. These may make it ill-suited for
make_shared, since those overloads will not be called - and presumably they exist for a reason.