Implement fallible C++ functions
diff --git a/tests/ffi/tests.cc b/tests/ffi/tests.cc
index 0ec2658..4f36f9b 100644
--- a/tests/ffi/tests.cc
+++ b/tests/ffi/tests.cc
@@ -1,6 +1,7 @@
 #include "tests/ffi/tests.h"
 #include "tests/ffi/lib.rs"
 #include <cstring>
+#include <stdexcept>
 
 extern "C" void cxx_test_suite_set_correct() noexcept;
 extern "C" tests::R *cxx_test_suite_get_box() noexcept;
@@ -91,6 +92,12 @@
   }
 }
 
+void c_try_return_void() {}
+
+size_t c_try_return_primitive() { return 2020; }
+
+size_t c_fail_return_primitive() { throw std::logic_error("logic error"); }
+
 extern "C" C *cxx_test_suite_get_unique_ptr() noexcept {
   return std::unique_ptr<C>(new C{2020}).release();
 }