How to implement in place overloads

[awni]

If you have a class bound via Pybin11, what's the right way to implemente inplace overloads so that the returned object is the same as the input object?

      .def(
          "__iadd__",
          [](array& a, const array& v) {  
            a += v;
            return a;
          },
          "other"_a)

When checking the ids they are different

x = array(1.0)
print(id(x))
x += y
print(id(x)) # different than first id

If that's not enough info to understand the issue, let me know i can provide a more complete example!

[jnooree]

When c++ lambda does not have return type specified and you return an lvalue, it defaults to return-by-value.

You'd rather explicitly specify the return type instead:

.def("__iadd__", [](array& a, const array& v) -> array& {
    a += v;
    return a;
}, "other"_a)

[awni]

Thanks, that's exactly what I was looking for!

[jnooree]

I also tricked for the exact same reason 🤣