US 32-073 16 [library] Imprecise wording for convertibility to bool

[wg21bot]

Library wording is insufficiently precise around convertibility to bool in many contexts.

Proposed change:

Adopt P2167 to resolve LWG 2114.

[jwakely]

The related issue is LWG 2114 Incorrect "contextually convertible to bool" requirements.

LWG already approved the paper as part of regular issue processing work and it will be on the Kona straw polls.

[jensmaurer]

Accepted.