Ambiguity in Section 17.2

[tmcopeland]

The relevant subsection is Object Safety Is Required for Trait Objects. The term "object-safe" (vis-à-vis traits) is initially introduced in its hyphenated form; but the hyphen is then dropped. This leads to ambiguity in the phrase "properties that make a trait object safe--" i.e. (trait object) (safe) vs. (trait) (object-safe). I would recommend that the hyphen be retained in the literature to resolve similar ambiguities. The compiler, on the other hand, also omits the hyphen, but appears to place the term in double quotes in error messages, such that there should be no ambiguity.