34 Execution control library [exec]

34.5 Queries [exec.queries]

34.5.1 forwarding_query [exec.fwd.env]

1
#
forwarding_query asks a query object whether it should be forwarded through queryable adaptors.
2
#
The name forwarding_query denotes a query object.
For some query object q of type Q, forwarding_query(q) is expression-equivalent to:
  • (2.1)
    MANDATE-NOTHROW(q.query(forwarding_query)) if that expression is well-formed.
    Mandates: The expression above has type bool and is a core constant expression if q is a core constant expression.
  • (2.2)
    Otherwise, true if derived_from<Q, forwarding_query_t> is true.
  • (2.3)
    Otherwise, false.