Overloading methods in C++

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1

Hello everyone,
Do you know if it is possible to bind overloaded methods? Like:

int get_size() const;
int get_size(int) const;

I tried:

ClassDB::bind_method(D_METHOD("get_size"), &my_class::get_size);
ClassDB::bind_method(D_METHOD("get_size", "test"), &my_class::get_size);

But it doesn’t worked.

2

Oh i see, well i think most classes just specify a defualt value for the “overloaded” function, as you cannot overload a function in gdscript.

Because this cant work in gdscript, just define the parameter get_size with a defualt value so you can call either variation.

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3

You may have to explicitly specify the type of your reference

int (*get_size_no_arg)() = &my_class::get_size; 
int (*get_size_one_arg)(int) = &my_class::get_size;
ClassDB::bind_method(D_METHOD("get_size"), get_size_no_arg)
ClassDB::bind_method(D_METHOD("get_size", "test"), get_size_one_arg);

Otherwise you could set a default value if that covers your usecase better

ClassDB::bind_method(D_METHOD("get_size"), &my_class::get_size, DEFVAL(0));
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4

I tried it, but godot’s editor only shows the first one I binded. When I bind the method without argument first:

ClassDB::bind_method(D_METHOD("get_size"), static_cast<size_t (Set::*)()>(&Set::get_size));
ClassDB::bind_method(D_METHOD("get_size", "test"), static_cast<size_t (Set::*)(int)>(&Set::get_size));

The editor only shows the method int get_size()

But, when I bind the method with one argument:

ClassDB::bind_method(D_METHOD("get_size", "test"), static_cast<size_t (Set::*)(int)>(&Set::get_size));
ClassDB::bind_method(D_METHOD("get_size"), static_cast<size_t (Set::*)()>(&Set::get_size));

The editor only shows the method int get_size(int)

I was trying not to use default values because I’m studying how to develop modules for godot and I haven’t found anywhere talking about method overloading.

5

I get it. Then there is no way to overload methods in a c++ module, even with different arguments types?

6

Probably not, if it isn’t a feature in GDScript it can’t be forced in C++.

Most newer languages move away from function overloading, usually handled better by generics/meta programming, and Godot has that generic Variant type you could support in your function.

For example clamp is a variant-typed function which does work in a overloaded fashion for Vectors, where as clampf is typed for only float, but it has the f suffix.

Constructors seem to be overloadable though, maybe only for base types like Vectors though.

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