--- /dev/null
+/*=============================================================================
+ Boost.Wave: A Standard compliant C++ preprocessor library
+ http://www.boost.org/
+
+ Copyright (c) 2020 Jeff Trull. Distributed under the Boost
+ Software License, Version 1.0. (See accompanying file
+ LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+=============================================================================*/
+
+//O --c++20
+//O -Werror
+
+// test using __VA_ARGS__ inside __VA_OPT__
+// JET: Wave seems to inject a space after some lparens
+
+#define sizedvec(TYPE, NAME, SIZE, ...) std::vector<TYPE> NAME(SIZE __VA_OPT__(, __VA_ARGS__))
+
+//R #line 20 "t_8_004.cpp"
+//R std::vector<int> foo( 12 );
+sizedvec(int, foo, 12);
+
+//R #line 24 "t_8_004.cpp"
+//R std::vector<double> bar( 3 , 42.0);
+sizedvec(double, bar, 3, 42.0);