chainerx_cc/chainerx/native/native_device/pool.cc
void Mean(const Array& a, const Axes& axis, const Array& out) {
    Device& device = a.device();
    device.backend().CallOp<SumOp>(a, axis, out);
    device.backend().CallOp<DivideASOp>(out, internal::CountItemsAlongAxes(a.shape(), axis), out);
}
// TODO(hvy): Use Device::Mean when implemented.
Use Device::Mean when implemented.
Use Device :: Mean when implemented .
void Mean(const Array& a, const Axes& axis, const Array& out) {
    Device& device = a.device();
    device.backend().CallOp<SumOp>(a, axis, out);
    device.backend().CallOp<DivideASOp>(out, internal::CountItemsAlongAxes(a.shape(), axis), out);
}
void Mean ( const Array & a , const Axes & axis , const Array & out ) { Device & device = a . device ( ) ; device . backend ( ) . CallOp < SumOp > ( a , axis , out ) ; device . backend ( ) . CallOp < DivideASOp > ( out , internal :: CountItemsAlongAxes ( a . shape ( ) , axis ) , out ) ; }
TODO(hvy): Use Device::Mean when implemented.
TODO ( hvy ) : Use Device :: Mean when implemented .