Classes can only be bound to a single lua_State

[keenanlang]

When using the class binding functions, it appears that once a class has been bound to a lua_State, another lua_State cannot also have access to the given class while the first lua_State still exists.

As a minimal display of the issue, referencing the Cat class from your example code:

lua_State* state1 = luaL_newstate();
lua_State* state2 = luaL_newstate();

luaaa::LuaClass<Cat> lc1(state1, "AwesomeCat");
lc1.ctor();

luaaa::LuaClass<Cat> lc2(state2, "AwesomeCat");
lc2.ctor();

lua_close(state1);
lua_close(state2);

Results in the following assertion failure:

luaaa.hpp:979: luaaa::LuaClass< <template-parameter-1-1> >::LuaClass(lua_State*, const char*, const luaL_Reg*) [with TCLASS = Cat; lua_State = lua_State; luaL_Reg = luaL_Reg]: Assertion `klassName == nullptr' failed.

Meanwhile, if you close the first state before proceeding to the second, there isn't a problem.

lua_State* state1 = luaL_newstate();
lua_State* state2 = luaL_newstate();

luaaa::LuaClass<Cat> lc1(state1, "AwesomeCat");
lc1.ctor();

lua_close(state1);

luaaa::LuaClass<Cat> lc2(state2, "AwesomeCat");
lc2.ctor();

lua_close(state2);

Using LuaModule in this way does not appear to have the same issue.