FAQ

What’s up with __cdecl and __stdcall?

If you’re having problem with functions that cannot be converted from void (__stdcall *)(int,int) to void (__cdecl*)(int,int). You can change the project settings to make the compiler generate functions with __cdecl calling conventions. This is a problem in developer studio.

What’s wrong with functions taking variable number of arguments?

You cannot register a function with ellipses in its signature. Since ellipses don’t preserve type safety, those should be avoided anyway.

Internal structure overflow in VC

If you, in visual studio, get fatal error C1204: compiler limit : internal structure overflow. You should try to split that compilation unit up in smaller ones. See Splitting up the registration and Splitting class registrations.

What’s wrong with precompiled headers in VC?

Visual Studio doesn’t like anonymous namespaces in its precompiled headers. If you encounter this problem you can disable precompiled headers for the compilation unit (cpp-file) that uses luabind.

error C1076: compiler limit - internal heap limit reached in VC

In visual studio you will probably hit this error. To fix it you have to increase the internal heap with a command-line option. We managed to compile the test suit with /Zm300, but you may need a larger heap then that.

error C1055: compiler limit : out of keys in VC

It seems that this error occurs when too many assert() are used in a program, or more specifically, the __LINE__ macro. It seems to be fixed by changing /ZI (Program database for edit and continue) to /Zi (Program database).

How come my executable is huge?

If you’re compiling in debug mode, you will probably have a lot of debug-info and symbols (luabind consists of a lot of functions). Also, if built in debug mode, no optimizations were applied, luabind relies on that the compiler is able to inline functions. If you built in release mode, try running strip on your executable to remove export-symbols, this will trim down the size.

Our tests suggests that cygwin’s gcc produces much bigger executables compared to gcc on other platforms and other compilers.

Can I register class templates with luabind?

Yes you can, but you can only register explicit instantiations of the class. Because there’s no Lua counterpart to C++ templates. For example, you can register an explicit instantiation of std::vector<> like this:

module(L)
[
    class_<std::vector<int> >("vector")
        .def(constructor<int>)
        .def("push_back", &std::vector<int>::push_back)
];

Do I have to register destructors for my classes?

No, the destructor of a class is always called by luabind when an object is collected. Note that Lua has to own the object to collect it. If you pass it to C++ and gives up ownership (with adopt policy) it will no longer be owned by Lua, and not collected.

If you have a class hierarchy, you should make the destructor virtual if you want to be sure that the correct destructor is called (this apply to C++ in general).

Fatal Error C1063 compiler limit : compiler stack overflow in VC

VC6.5 chokes on warnings, if you are getting alot of warnings from your code try suppressing them with a pragma directive, this should solve the problem.

Crashes when linking against luabind as a dll in Windows

When you build luabind, Lua and you project, make sure you link against the runtime dynamically (as a dll).

I cannot register a function with a non-const parameter

This is because there is no way to get a reference to a Lua value. Have a look at out_value and pure_out_value policies.