gcc: fix warnings

lib/include/irritator/io.hpp

@@ -231,7 +231,11 @@ private:
             return status::success;
         });
 
+        irt_return_if_bad(ret);
+
         map.emplace_back(id, mdl);
+
+        return status::success;
     }
 
     bool read(none& /*dyn*/) noexcept
@@ -455,7 +459,7 @@ struct writer
     }
 
 private:
-    void write(const none& dyn) noexcept
+    void write(const none& /*dyn*/) noexcept
     {
         std::fprintf(file, "none\n");
     }

lib/test/public-api.cpp

@@ -1021,7 +1021,8 @@ main()
         expect(sim.connect(integrator_b.y[0], quantifier_b.x[0]) ==
                irt::status::success);
 
-        irt::dot_writer(stdout)(sim);
+        irt::dot_writer dw(stdout);
+        dw(sim);
 
         file_output fo_a("lotka-volterra_a.csv");
         file_output fo_b("lotka-volterra_b.csv");
@@ -1202,7 +1203,8 @@ main()
                irt::status::success);
         expect(sim.connect(constant.y[0], sum_d.x[1]) == irt::status::success);
 
-        irt::dot_writer(stdout)(sim);
+        irt::dot_writer dw(stdout);
+        dw(sim);
 
         file_output fo_a("izhikevitch_a.csv");
         file_output fo_b("izhikevitch_b.csv");