tmp/tmph89r82rn/{from.md → to.md}
RENAMED
|
@@ -0,0 +1,42 @@
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
| 1 |
+
## Operation states <a id="exec.opstate">[[exec.opstate]]</a>
|
| 2 |
+
|
| 3 |
+
### General <a id="exec.opstate.general">[[exec.opstate.general]]</a>
|
| 4 |
+
|
| 5 |
+
The `operation_state` concept defines the requirements of an operation
|
| 6 |
+
state type [[exec.async.ops]].
|
| 7 |
+
|
| 8 |
+
``` cpp
|
| 9 |
+
namespace std::execution {
|
| 10 |
+
template<class O>
|
| 11 |
+
concept operation_state =
|
| 12 |
+
derived_from<typename O::operation_state_concept, operation_state_t> &&
|
| 13 |
+
requires (O& o) {
|
| 14 |
+
start(o);
|
| 15 |
+
};
|
| 16 |
+
}
|
| 17 |
+
```
|
| 18 |
+
|
| 19 |
+
If an `operation_state` object is destroyed during the lifetime of its
|
| 20 |
+
asynchronous operation [[exec.async.ops]], the behavior is undefined.
|
| 21 |
+
|
| 22 |
+
[*Note 1*: The `operation_state` concept does not impose requirements
|
| 23 |
+
on any operations other than destruction and `start`, including copy and
|
| 24 |
+
move operations. Invoking any such operation on an object whose type
|
| 25 |
+
models `operation_state` can lead to undefined behavior. — *end note*]
|
| 26 |
+
|
| 27 |
+
The program is ill-formed if it performs a copy or move construction or
|
| 28 |
+
assignment operation on an operation state object created by connecting
|
| 29 |
+
a library-provided sender.
|
| 30 |
+
|
| 31 |
+
### `execution::start` <a id="exec.opstate.start">[[exec.opstate.start]]</a>
|
| 32 |
+
|
| 33 |
+
The name `start` denotes a customization point object that starts
|
| 34 |
+
[[exec.async.ops]] the asynchronous operation associated with the
|
| 35 |
+
operation state object. For a subexpression `op`, the expression
|
| 36 |
+
`start(op)` is ill-formed if `op` is an rvalue. Otherwise, it is
|
| 37 |
+
expression-equivalent to `MANDATE-NOTHROW(op.start())`.
|
| 38 |
+
|
| 39 |
+
If `op.start()` does not start [[exec.async.ops]] the asynchronous
|
| 40 |
+
operation associated with the operation state `op`, the behavior of
|
| 41 |
+
calling `start(op)` is undefined.
|
| 42 |
+
|