deduction guides for std::scoped_allocator_adaptor

Header: <scoped_allocator>

One deduction guide is provided for std::scoped_allocator_adaptor to make it possible to deduce its outer allocator.

# Declarations

template< class OuterAlloc, class... InnerAllocs >
scoped_allocator_adaptor( OuterAlloc, InnerAllocs... )
-> scoped_allocator_adaptor<OuterAlloc, InnerAllocs...>;

(since C++17)

# Example

This section is incompleteReason: no example