23 Iterators library [iterators]

23.3 Iterator requirements [iterator.requirements]

23.3.7 Common algorithm requirements [alg.req]

23.3.7.2 Concept IndirectlyMovable [alg.req.ind.move]

The IndirectlyMovable concept specifies the relationship between a Readable type and a Writable type between which values may be moved.
template<class In, class Out>
  concept IndirectlyMovable =
    Readable<In> &&
    Writable<Out, iter_rvalue_reference_t<In>>;
The IndirectlyMovableStorable concept augments IndirectlyMovable with additional requirements enabling the transfer to be performed through an intermediate object of the Readable type's value type.
template<class In, class Out>
  concept IndirectlyMovableStorable =
    IndirectlyMovable<In, Out> &&
    Writable<Out, iter_value_t<In>> &&
    Movable<iter_value_t<In>> &&
    Constructible<iter_value_t<In>, iter_rvalue_reference_t<In>> &&
    Assignable<iter_value_t<In>&, iter_rvalue_reference_t<In>>;
Let i be a dereferenceable value of type In.
In and Out model IndirectlyMovableStorable<In, Out> only if after the initialization of the object obj in
iter_value_t<In> obj(ranges::iter_move(i));
obj is equal to the value previously denoted by *i.
If iter_­rvalue_­reference_­t<In> is an rvalue reference type, the resulting state of the value denoted by *i is valid but unspecified ([lib.types.movedfrom]).