1 files changed, 11 insertions, 3 deletions
diff --git a/example/option_example/example.cc b/example/option_example/example.cc
index e35f73b..c784dec 100644
--- a/example/option_example/example.cc
+++ b/example/option_example/example.cc
@@ -1,15 +1,23 @@
 #include <ocl/crc_hash.hpp>
 #include <ocl/print.hpp>
 #include <ocl/option.hpp>
-// #include <ocl/is_same.hpp>
 
+struct invalid_callable {
+    explicit invalid_callable() = default;
+    void operator()(const char* reason)
+    {
+        ocl::detail::throw_runtime_error(BOOST_CURRENT_LOCATION.to_string());
+    }
+};
+
+/// \brief Option Monad example
 int main(int argc, char** argv)
 {
     ocl::option opt{ocl::eval_eq(nullptr, nullptr)};
-    opt.expect("is incorrect");
+    opt.expect("option::incorrect");
 
     ocl::option opt2{ocl::eval_eq(argv, nullptr)};
-    opt2.expect("is incorrect");
+    opt2.expect<invalid_callable>("option::incorrect");
 
 	return 0;
 }