Add test from bugreport, provide compile time diagnostics for such cases (#85)

Fixes https://github.com/apolukhin/Boost.DLL/issues/47

include/boost/dll/detail/demangling/msvc.hpp

@@ -76,7 +76,7 @@ void mangled_storage_impl::trim_typename(std::string & val)
         static constexpr char class_ [7] = "class ";
         static constexpr char struct_[8] = "struct ";
 
-        if (equal(begin(class_), end(class_)-1, val.begin())) //aklright, starts with 'class '
+        if (equal(begin(class_), end(class_)-1, val.begin()))
             val.erase(0, 6);
         else if (val.size() >= 7)
             if (equal(begin(struct_), end(struct_)-1, val.begin()))
@@ -98,7 +98,7 @@ namespace parser {
         parser::try_consume_prefix(s, prefix);
         return true;
     }
-    
+
     inline void consume_ptrs(boost::core::string_view& s) {
         do {
             while (parser::try_consume_prefix(s, " ")) {}
@@ -126,6 +126,15 @@ namespace parser {
         parser::ignore_prefix(s, "struct ");
 
         const auto& mangled_name = ms.get_name<T>();
+
+        static_assert(
+            !std::is_function<typename std::remove_pointer<T>::type>::value,
+            "boost::dll::smart_library on Windows platform does not support "
+            "functions that accept functions. If you wish to see such support "
+            "- please provide a working PR on github with sufficient tests. "
+            "Otherwise simplify the function. For example, use `void*` "
+            "parameter instead of a function pointer. "
+        );
         if (!parser::try_consume_prefix(s, mangled_name)) {
             return false;
         }

test/Jamfile.v2

@@ -100,6 +100,7 @@ project
         [ run shared_library_concurrent_load_test.cpp /boost/thread//boost_thread : : library1 library2 my_plugin_aggregator refcounting_plugin : <link>shared ]
         [ run cpp_mangle_test.cpp : : cpp_plugin ]
         [ run cpp_mangling.cpp ]
+        [ compile-fail cpp_mangling1_cf.cpp ]
         [ run cpp_load_test.cpp   : : cpp_plugin ]
         [ run cpp_import_test.cpp   : : cpp_plugin ]
         [ run template_method_linux_test.cpp : : cpp_plugin ]

test/cpp_mangling1_cf.cpp

@@ -0,0 +1,30 @@
+// Copyright 2024 Antony Polukhin
+//
+// 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)
+
+// For more information, see http://www.boost.org
+
+#include <boost/dll/detail/demangling/msvc.hpp>
+
+struct CallbackInfo;
+
+#ifdef _MSC_VER
+typedef void(__stdcall* Callback)(CallbackInfo* pInfo);
+#else
+typedef void(*Callback)(CallbackInfo* pInfo);
+#endif
+
+
+int main() {
+    namespace parser = boost::dll::detail::parser;
+    boost::dll::detail::mangled_storage_impl ms;
+    
+    // The following case of mangling is not supported at the moment. Make 
+    // sure that we detect it on compile time.
+    parser::is_mem_fn_with_name<int, void(*)(Callback)>("set_callback", ms)
+        ("public: void __cdecl int::set_callback(void (__cdecl*)(struct CallbackInfo * __ptr64)) __ptr64")
+    ;
+}
+