How to confirm a huge array never been copied when passing it into python?

[leonleeann]

I need return a static const array from c++ to python. It is very huge so I want it would NOT be copied.

My question: How to confirm that it is NOT copied?

The c++ codes:

double buff[] = { 0.0, 1.1, 2.2, 3.3, 4.4, 5.5, 6.6, 7.7, 8.8 };
PYBIND11_MODULE( ModuleCpp, m ) {
    m.def( "raw_buff", []()->py::memoryview {
        std::cerr << "raw_buff:" << buff << std::endl;
        return py::memoryview::from_buffer(
            buff, sizeof( double ),
            py::format_descriptor<double>::value,
            { 2, 4 }, { 4 * sizeof( double ), sizeof( double ) }, true );
    }, "RawBuffer" );
};

The python codes:

import ModuleCpp
if __name__ == "__main__":
    #help( ModuleCpp )
    rb = ModuleCpp.raw_buff()
    print( hex( id( rb ) ) )
    print( hex( id( rb[0, 0] ) ) )
    # the addrs above are NOT same as the one in c++

[virtuald]

A memoryview doesn't copy its data, it's just a reference to it. What is there to confirm?