Proposed resolution:

This wording is relative to N4431.

1. Change [util.smartptr.shared.const] as follows:

   template<class Y> explicit shared_ptr(Y* p);
   

   […]

   -4- Effects: Constructs a shared_ptr object that owns the pointer p. If an exception is thrown, delete p is called.

   […]

   -7- Exception safety: If an exception is thrown, delete p is called.

   template <class Y, class D> shared_ptr(Y* p, D d);
   template <class Y, class D, class A> shared_ptr(Y* p, D d, A a);
   template <class D> shared_ptr(nullptr_t p, D d);
   template <class D, class A> shared_ptr(nullptr_t p, D d, A a);
   

   […]

   -9- Effects: Constructs a shared_ptr object that owns the object p and the deleter d. The second and fourth constructors shall use a copy of a to allocate memory for internal use. If an exception is thrown, d(p) is called.

   […]

   -12- Exception safety: If an exception is thrown, d(p) is called.

   […]

   template <class Y> explicit shared_ptr(const weak_ptr<Y>& r);
   

   […]

   -24- Effects: Constructs a shared_ptr object that shares ownership with r and stores a copy of the pointer stored in r. If an exception is thrown, the constructor has no effect.

   […]

   -27- Exception safety: If an exception is thrown, the constructor has no effect.

   template <class Y, class D> shared_ptr(unique_ptr<Y, D>&& r);
   

   […]

   -29- Effects: Equivalent to shared_ptr(r.release(), r.get_deleter()) when D is not a reference type, otherwise shared_ptr(r.release(), ref(r.get_deleter())). If an exception is thrown, the constructor has no effect.

   -30- Exception safety: If an exception is thrown, the constructor has no effect.

[ 2015-06, Telecon ]

Move to Tentatively Ready.

[util.smartptr.shared.const] includes several "Exception safety" elements, but that is not one of the elements defined in 17.5.1.4 [structure.specifications]. We should either define what it means, or just move those sentences into the Effects: clause.