Inconsistent behaviour when multiplying CWiseUnaryViews

Submitted by Andrew Johnson

Assigned to Nobody

Link to original bugzilla bug (#1730)
Version: 3.3 (current stable)

Description

Initially discussed on SO here

Compilation errors occur when attempting to multiplying two CWiseUnaryViews together, but only under particular constructions.

Given a view that simply returns the same matrix, the compilation fails with an error about coefReff : https://godbolt.org/z/JYQb3d

Given a view that returns the double from a struct nested in another struct, the compilation fails unless the intermediary struct also contains a double: https://godbolt.org/z/7nvhqx

However, this intermediary double isn't required if the nested value to be returned is a float: https://godbolt.org/z/GJUZ41