Merge pull request #1725 from RobertLeahy/completion_token_20251229

asioexec::completion_token: Conversion From Mutable Lvalue to Rvalue

Author: ericniebler

include/asioexec/completion_token.hpp

@@ -92,7 +92,7 @@ namespace asioexec {
         at_least_as_qualified_v<std::remove_reference_t<T>, std::remove_reference_t<U>>
         && (
           //  Reference type must agree except...
-          (std::is_lvalue_reference_v<T> == std::is_lvalue_reference_v<T>) ||
+          (std::is_lvalue_reference_v<T> == std::is_lvalue_reference_v<U>) ||
           //  ...special rules for const& which allows rvalues to bind thereto
           (std::is_lvalue_reference_v<T> && std::is_const_v<std::remove_reference_t<T>>) ))
 #endif

test/asioexec/test_completion_token.cpp

@@ -1018,4 +1018,19 @@ namespace {
     CHECK(ctx.stopped());
   }
 
+  TEST_CASE(
+    "Asio operations which declare completion by value but send a mutable lvalue work",
+    "[asioexec][completion_token]") {
+    const auto initiating_function = [](auto&& token) {
+      return asio_impl::async_initiate<decltype(token), void(int)>(
+        [](auto&& h) {
+          int i = 5;
+          std::forward<decltype(h)>(h)(i);
+        },
+        token);
+    };
+    auto op = ::stdexec::connect(initiating_function(completion_token), expect_value_receiver{5});
+    ::stdexec::start(op);
+  }
+
 } // namespace