Accessing array of shared_ptr

The bracket notation is defined to work with pointer types (and you're right that, given array array, the expression array decays to an expression with such a type which points to the first element) but, despite its function, std::shared_ptr is not a pointer type.

You would have to obtain the raw pointer first:

array.get()[n];

Where n is, of course, a valid array subscript.

This is also the case with std::unique_ptr (though note that, in that case, you do not need to supply your own deleter!).