implicit type casting with postgres

[NPCRUS]

having a field of string on a table

case class T[T[_]](
  field: T[String]
)

query:

db.run(T.select.filter(t.field `=` 2))

fails with

org.postgresql.util.PSQLException: ERROR: operator does not exist: character varying = integer
  Hint: No operator matches the given name and argument types. You might need to add explicit type casts.
  Position: 205

when using postgres, i guess i would expect either implicit typecasting of compile error