O'Reilly logo
  • Dustin Waybright thinks this is interesting:

n example for manipulation of the filtered column is applying a function to it, as in F(col1) = 10, where F is some function. There are some exceptions to this rule, but they are very uncommon.

From

Cover of Training Kit (Exam 70-461): Querying Microsoft® SQL Server® 2012

Note

Applying a function to a filtered column prevents SQL Server from making use of available indices.