Global function as member function.

[aster2013]

When a global function with first argument is Object& or Object*, Can I treat is as a member function for usertype. e.g.

float Length(Vector2& vec)
{
    return sqrtf(vec.x * vec.x + vec.y * vec.y);
}

In Lua:

local vec = Vector2:new(10, 10)
local length = vec:Length()

Now I can register it as a static function for usertype.

[satoren]

Yes.
Can use lambda,functor,static function if first argument is same type.

state["A"].setClass(kaguya::UserdataMetatable<A>()
    .setConstructors<A()>()
    .addStaticFunction("lambdafn", [](A* self,int v){self->setValue(v);})
    );

local a = ABC.new()
a:lambdafn(3) --equal setValue(3)
a.lambdafn(a,3) --equal to above

[aster2013]

addStaticFunction may not the best name for it situation. I prefer to addMemberFunction.

[satoren]

If implement addMemberFunction for global function, need first argument type check.
but it implement for C++03 is difficult.

[aster2013]

Yes, another question:
When class has setter and getter function, can I treat it as property?

class Class
{
    void SetValue(int value);
    int GetValue() const;
};

.addProperty("value", &Class::GetValue, &Class::SetValue)

[satoren]

Can not now. Try to make because it is easy.

[aster2013]

Thinks, but as convention, it is better make getter as first argumention.

template<typename GetType, typename SetType>
        UserdataMetatable& addProperty(const char* name, GetType(class_type::*getter)()const, void (class_type::*setter)(SetType) ) {}

[satoren]

It's changed.

[aster2013]

Great!, but

template<typename SetType, typename GetType>
UserdataMetatable& addProperty(const char* name, GetType(class_type::*getter)()const, void (class_type::*setter)(SetType))

First template arguments is SetType, It is misleading.