cxxrtl: fix a few gcc warnings.

diff --git a/backends/cxxrtl/cxxrtl.h b/backends/cxxrtl/cxxrtl.h
index c988c9e80a4f2eea2bcf865ed44cc59a665de9be..c6dc0e892149c01cf79bfaa7d259f785563eb730 100644 (file)
--- a/backends/cxxrtl/cxxrtl.h
+++ b/backends/cxxrtl/cxxrtl.h
@@ -608,6 +608,7 @@ struct memory {
                // This utterly reprehensible construct is the most reasonable way to apply a function to every element
                // of a parameter pack, if the elements all have different types and so cannot be cast to an initializer list.
                auto _ = {std::move(std::begin(init.data), std::end(init.data), data.begin() + init.offset)...};
+               (void)_;
        }
 
        // An operator for direct memory reads. May be used at any time during the simulation.
@@ -676,10 +677,8 @@ struct metadata {
 
        // In debug mode, using the wrong .as_*() function will assert.
        // In release mode, using the wrong .as_*() function will safely return a default value.
-       union {
-               const unsigned  uint_value = 0;
-               const signed    sint_value;
-       };
+       const unsigned    uint_value = 0;
+       const signed      sint_value = 0;
        const std::string string_value = "";
        const double      double_value = 0.0;
 
@@ -799,7 +798,9 @@ struct module {
                return deltas;
        }
 
-       virtual void debug_info(debug_items &items, std::string path = "") {}
+       virtual void debug_info(debug_items &items, std::string path = "") {
+               (void)items, (void)path;
+       }
 };
 
 } // namespace cxxrtl