**Description of the false positive** It appears the rule does not consider structs passed-by-reference as being read. **URL to the alert on the project page on LGTM.com** https://lgtm.com/projects/g/dotnet/roslyn/snapshot/c9e0dd1ec0e440897388bbd55184fb53a555e3a4/files/src/Compilers/CSharp/Portable/Binder/Binder_Expressions.cs?sort=name&dir=ASC&mode=heatmap#x395aadf443576ef9:1