Created on 2021-01-18.00:00:00 last changed 46 months ago
Rationale (February, 2021):
The specification is as intended; o is converted to an lvalue if it is an xvalue result of the temporary materialization conversion. e is used in both bullets 3.7 and 3.8; if it were an xvalue instead of an lvalue, the call to await_suspend could steal e's resources and leave the call to await_resume with a defunct object, which would be undesirable.
According to 7.6.2.4 [expr.await] bullets 3.3 and 3.4,
Evaluation of an await-expression involves the following auxiliary types, expressions, and objects:
...
o is determined by enumerating the applicable operator co_await functions for an argument a (12.2.2.3 [over.match.oper]), and choosing the best one through overload resolution (12.2 [over.match]). If overload resolution is ambiguous, the program is ill-formed. If no viable functions are found, o is a. Otherwise, o is a call to the selected function with the argument a. If o would be a prvalue, the temporary materialization conversion (7.3.5 [conv.rval]) is applied.
e is an lvalue referring to the result of evaluating the (possibly-converted) o.
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However, the temporary materialization conversion produces an xvalue, not an lvalue. Should e be a glvalue instead of an lvalue?
| History | |||
|---|---|---|---|
| Date | User | Action | Args |
| 2021-02-17 00:00:00 | admin | set | messages: + msg6507 |
| 2021-01-18 00:00:00 | admin | create | |