add test

Author: ludviggunne

test/testfunctions.cpp

@@ -86,6 +86,7 @@ class TestFunctions : public TestFixture {
         TEST_CASE(checkMissingReturn5);
         TEST_CASE(checkMissingReturn6); // #13180
         TEST_CASE(checkMissingReturn7); // #14370 - FN try/catch
+        TEST_CASE(checkMissingReturn8);
         TEST_CASE(checkMissingReturnStdInt); // #14482 - FN std::int32_t
 
         // std::move for locar variable
@@ -1927,6 +1928,14 @@ class TestFunctions : public TestFixture {
         ASSERT_EQUALS("[test.cpp:3:19]: (error) Found an exit path from function with non-void return type that has missing return statement [missingReturn]\n", errout_str());
     }
 
+    void checkMissingReturn8() {
+        const Settings s = settingsBuilder(settings).cpp(Standards::CPP20).build();
+        check("boost::asio::awaitable<void> test() {\n"
+              "        co_return;\n"
+              "}\n",s);
+        ASSERT_EQUALS("", errout_str());
+    }
+
     void checkMissingReturnStdInt() {// #14482 - FN
         check("std::int32_t f() {}\n");
         ASSERT_EQUALS("[test.cpp:1:19]: (error) Found an exit path from function with non-void return type that has missing return statement [missingReturn]\n", errout_str());