33 Execution control library [exec]

33.5 Queries [exec.queries]

33.5.1 forwarding_query [exec.fwd.env]

forwarding_query asks a query object whether it should be forwarded through queryable adaptors.
The name forwarding_query denotes a query object.
For some query object q of type Q, forwarding_query(q) is expression-equivalent to:
  • 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.
  • Otherwise, true if derived_from<Q, forwarding_query_t> is true.
  • Otherwise, false.