Importing more headers than required? [How to write a vector or integer's coordinates in R's cpp11?]

[pachadotdev]

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As the answer to my StackOverflow question says.

This example shows that the documentation could be improved.

[[cpp11::register]] integers dummyexample(integers x1, integers x2) {
  int n = x1.size();
  writable::integers y1(n);
  writable::integers y2(n);

  // add content to y2
  // y2_1 = x2_1^2, y2_2 = x2_2^2, ...
  for (int i = 0; i < n; i++) { y2[i] = pow(x2[i], 2); }

  // then

  for (int i = 0; i < n; i++) {
    // error: ambiguous overload for ‘operator=’
    // y1[i] = y2[i];

    // this should resolve the ambiguity
    // y1.at(i) = y2.at(i);
    // not really, also error: ambiguous overload for ‘operator=’

    // maybe
    // y1.operator[](i).operator=(y2.operator[](i));

    // not either
    // int temp = y2[i];
    // y1[i] = temp;

    // 0 + y2_i works, but why?
    y1[i] = 0 + y2[i];
  }

  return y1;
}

Taking from SamR's answer:

y1[i] and y2[i] are elements of writable integer vectors, and are of type cpp11::writable::r_vector::proxy. It appears that the equals operator for this type has been defined in two places:

1. r_vector.hpp line 241: proxy& operator=(const T& rhs);
2. integers.hpp line 59: inline typename r_vector<int>::proxy& r_vector<int>::proxy::operator=(const int& rhs)