Merge pull request #39 from dietmarkuehl/HEAD

Head

Author: dietmarkuehl

docs/overview.md

@@ -252,9 +252,21 @@ Required members for <code>_Token_</code>:
 - <code>std::copyable&lt;_Token_&gt;</code>
 - <code>std::equality_comparable&lt;_Token_&gt;</code>
 - <code>std::swapable&lt;_Token_&gt;</code>
-<blockquote>
+<div>
+<details>
+<summary>Example: concept use</summary>
+<div>
+
+```c++
+static_assert(std::execution::unstoppable_token<std::execution::never_stop_token>);
+static_assert(std::execution::unstoppable_token<std::execution::stop_token>);
+static_assert(std::execution::unstoppable_token<std::execution::inline_stop_token>);
+```
+</div>
+</details>
 <details>
 <summary>Example: polling</summary>
+<div>
 This example shows a sketch of using a <code>stoppable_token&lt;_Token_&gt;</code> to cancel an active operation. The computation in this example is represented as `sleep_for`.
 
 ```c++
@@ -266,9 +278,11 @@ void compute(std::stoppable_token auto token)
     }
 }
 ```
+</div>
 </details>
 <details>
 <summary>Example: inactive</summary>
+<div>
 This example shows how an <code><a href=‘#operation-state’>operation_state</a></code> can use the <code>callback_type</code> together with a <code>_token_</code> to get notified when cancellation is requested.
 
 ```c++
@@ -305,7 +319,7 @@ struct example_state
     }
     auto stop() {
         unregister_work(this);
-        if (--this->outstanding == 0u)
+        if (—this->outstanding == 0u)
             std::execution::set_stopped(std::move(this->receiver));
     }
     auto complete() {
@@ -316,11 +330,25 @@ struct example_state
     }
 };    
 ```
+</div>
 </details>
-</blockquote>
+</div>
 </details>
 <details>
-<summary><code>unstoppable_token&lt;Token&gt;</code> TODO</summary>
+<summary><code>unstoppable_token&lt;_Token_&gt;</code></summary>
+The concept <code>unstoppable_token&lt;Token&gt;</code> is modeled by a <code>_Token_</code> if <code>stoppable_token&lt;_Token_&gt;</code> is true and it can statically be determined that both <code>_token_.stop_requested()</code> and <code>_token_.stop_possible()</code> are `constexpr` epxressions yielding `false`. This concept is primarily used to avoid extra work when using stop tokens which will never indicate that cancellations are requested.
+<div>
+<details>
+<summary>Example</summary>
+The concept yields `true` for the <code><a href=‘#never-stop-token’>std::execution::never_stop_token</a></code>:
+
+```c++
+static_assert(std::execution::unstoppable_token<std::execution::never_stop_token>);
+static_assert(not std::execution::unstoppable_token<std::execution::stop_token>);
+static_assert(not std::execution::unstoppable_token<std::execution::inline_stop_token>);
+```
+</details>
+</div>
 </details>
 
 ## Queries

examples/stopping.cpp

@@ -70,7 +70,7 @@ struct inject_cancel_sender
 
     template <typename Receiver>
     auto connect(Receiver&& recv) && {
-        return ex::connect(std::move(sender), receiver<Receiver>(std::forward<Receiver>(recv), this->token));
+        return ex::connect(std::move(sender), receiver<Receiver>{std::forward<Receiver>(recv), this->token});
     }
 };