将 irrlicht 类注册到 angelscript 中会给出<未解析的重载函数类型>

我试图注册以下函数从Irrlicht, dimension2df:

template <class U>
dimension2d<T>& operator=(const dimension2d<U>& other)
{ 
    Width = (T) other.Width;
    Height = (T) other.Height;
    return *this;
}

这是完整的源文件:http://irrlicht.sourceforge.net/docu/dimension2d_8h_source.html

下面是我在angelscript中注册重载操作符=的c++代码:

r = engine->RegisterObjectMethod("dimension2f", "bool opEquals(const dimension2f &in) const", asFUNCTIONPR(operator==, (dimension2df&), bool),asCALL_CDECL_OBJFIRST); assert(r >= 0);

E:pbmain.cpp|295|error: invalid static_cast from type '<unresolved overloaded function type>' to type 'bool (*)(irr::core::dimension2df&)'|

查看文档，它描述了注册操作符函数的方法:

struct Vector3
{
Vector3();
Vector3(const Vector3 &other);
Vector3(float x, float y, float z);
Vector3 &operator=(const Vector3 &other);
Vector3 &operator+=(const Vector3 &other);
Vector3 &operator-=(const Vector3 &other);
Vector3 &operator*=(float scalar);
Vector3 &operator/=(float scalar);
friend bool operator==(const Vector3 &a, const Vector3 &b);
friend bool operator!=(const Vector3 &a, const Vector3 &b);
friend Vector3 operator+(const Vector3 &a, const Vector3 &b);
friend Vector3 operator-(const Vector3 &a, const Vector3 &b);
friend Vector3 operator*(float s, const Vector3 &v);
friend Vector3 operator*(const Vector3 &v, float s);
friend Vector3 operator/(const Vector3 &v, float s);
float x;
float y;
float z;
};
r = engine->RegisterObjectMethod("vector3", "bool opEquals(const vector3 &in) const", asFUNCTIONPR(operator==, (const Vector3&, const Vector3&), bool), asCALL_CDECL_OBJFIRST); assert( r >= 0 );

我尽量照着例子做，但是这个问题真的把我难住了。