comptime/returnvector.cpp

The following code example is taken from the book
C++20 - The Complete Guide by Nicolai M. Josuttis, Leanpub, 2021
The code is licensed under a Creative Commons Attribution 4.0 International License.

---

// raw code

#include <vector>

constexpr auto returnVector()
{
  std::vector<int> v{0, 8, 15};
  v.push_back(42);
  //...

  return v;
}

constexpr auto returnVectorSize()
{
  auto coll = returnVector();
  return coll.size();
}

int main()
{
  //constexpr auto coll = returnVector(); // ERROR
  constexpr auto tmp = returnVectorSize();  // OK
  //...
}