Type conversions from JavaScript to C++ in V8(blog.scottfrees.com)

    // js
    var x = new Float64Array([1, 2, 3]);
    binding(x);

    // c++
    void binding(const v8::FunctionCallbackInfo<v8::Value>& info) {
        void *data = info[0].As<v8::Float64Array>()->Buffer()->GetContents().Data();
        double *x = reinterpret_cast<double*>(data);

        // do whatever, e.g.
        x[0] = 0;
    }