Stop requiring rvalue references for co_return

Author: dermesser

test/async_work_test.cc

@@ -1,20 +1,19 @@
 
-#include <atomic>
-#include <functional>
-#include <stdexcept>
-#include <thread>
+#include <fcntl.h>
+#include <fmt/core.h>
+#include <fmt/ranges.h>
+#include <gtest/gtest.h>
 #include <uv.h>
 
 #include "test_util.h"
-
 #include "uvco/async_work.h"
 #include "uvco/loop/loop.h"
 #include "uvco/promise/promise.h"
 
-#include <fcntl.h>
-#include <fmt/core.h>
-#include <fmt/ranges.h>
-#include <gtest/gtest.h>
+#include <atomic>
+#include <functional>
+#include <stdexcept>
+#include <thread>
 #include <vector>
 
 namespace {
@@ -115,7 +114,8 @@ TEST(AsyncWorkTest, execptionThrownForValue) {
 }
 
 TEST(AsyncWorkTest, workNotAwaited) {
-  // Test that work on the threadpool finishes even if the main function returns early.
+  // Test that work on the threadpool finishes even if the main function returns
+  // early.
   bool workRan = false;
   auto work = [&workRan]() -> void {
     std::this_thread::sleep_for(std::chrono::milliseconds{10});

test/pqxx_test.cc

@@ -22,7 +22,7 @@ constexpr std::string_view schemaTearDown = R"(
 DROP TABLE test;
 )";
 
-constexpr std::string_view connectionString = "dbname=lbo";
+constexpr std::string_view connectionString = "dbname=lbo user=lbo";
 
 // This test obviously only runs if you have a PostgreSQL server running. Change
 // the connection string to match your setup.

uvco/async_work.h

@@ -39,7 +39,7 @@ Promise<R> submitWork(const Loop &loop, std::function<R()> work) {
   if (result->index() == 1) {
     std::rethrow_exception(std::get<std::exception_ptr>(*result));
   }
-  co_return std::move(std::get<R>(*result));
+  co_return std::get<R>(std::move(*result));
 }
 
 template <>

uvco/promise/multipromise.h

@@ -309,20 +309,13 @@ template <typename T> class Generator {
   /// still moved into the generator's slot, but the generator is not resumed.
   /// Upon the next `co_await`, the returned `MultiPromiseAwaiter_` will
   /// immediately return the value without resuming the generator.
-  YieldAwaiter_ yield_value(T &&value) {
+  YieldAwaiter_ yield_value(T value) {
     BOOST_ASSERT(!core_->slot);
     core_->slot = std::move(value);
     core_->resume();
     return YieldAwaiter_{*core_};
   }
 
-  YieldAwaiter_ yield_value(const T &value) {
-    BOOST_ASSERT(!core_->slot);
-    core_->slot = value;
-    core_->resume();
-    return YieldAwaiter_{*core_};
-  }
-
 private:
   /// A `YieldAwaiter_` suspends a coroutine returning a MultiPromise (i.e. a
   /// generator) and resumes it when the value is read by the awaiting

uvco/promise/promise.h

@@ -310,7 +310,7 @@ template <typename T> class Coroutine {
 
   /// Part of the coroutine protocol: Called by `co_return`. Schedules the
   /// awaiting coroutine for resumption.
-  void return_value(T &&value) {
+  void return_value(T value) {
     // Probably cancelled.
     if (core_->slot.has_value() && core_->slot->index() == 1) {
       return;

uvco/uds.cc

@@ -46,7 +46,7 @@ Promise<UnixStream> UnixStreamClient::connect(std::string_view path) {
   // open but not connected handle.
   try {
     UnixStream connection = co_await awaiter;
-    co_return std::move(connection);
+    co_return connection;
   } catch (const UvcoException &e) {
     maybeError = e;
   }