Pass a string Recursively without Recreation

Question

I answered a question here: https://stackoverflow.com/a/28862668/2642059 Where I needed to use recurrence to step through a string. I wanted to use a cons

Answer 1

Write your own array_view. It is a few dozen lines of code.

Use std::find to replace both algorithms. In one case, use reverse iterators. (or write a range-based find and range-based backwards)

Use {T*,T*} ctor to recurse.

array_view foo(array_view bar)

Here is a primitive array_view:

template
struct array_view {
  using mutable_T = typename std::remove_reference::type;
  // 3 primitive functions:
  T* begin() const { return b; }
  T* end() const { return e; }
  array_view(T* s, T* f):b(s), e(f) {};
  // everything else based on them:
  size_t size() const { return end()-begin(); }
  array_view(T* s, size_t l):array_view(s,s+l) {}
  array_view():array_view(nullptr,  nullptr) {}
  // repeat next 3 for string, array, initializer list, C array as required:
  template
  array_view( std::vector& v ):array_view(v.data(), v.size()) {}
  // may not compile for non-const T, but that is ok  you get an error:
  template
  array_view( std::vectorconst & v ):array_view(v.data(), v.size()) {}
  // in a better world, you'd SFINAE remove the above from consideration
  // consider it for your next iteration of array_view.
  // conversion to containers:
  template
  explicit operator std::vector() const {
    return convert_to< std::vector >();
  }
  template
  C convert_to() const {
    C retval(begin(), end());
    return retval;
  }

  // utility functions:
  T& front() const { return *begin(); }
  T& back() const { return std::prev(*end()); }
  // Also rbegin, rend, and whatever else you find you are missing

  // inspired by std::experimental:
  void pop_front() { *this = {std::next(begin()), end()}; }
  void pop_back() { *this = {begin(), std::prev(end())}; }
  // but I find direct use of `view = {x,y}` almost as good
  // these kind of operations are the ONLY ones that are non-const
  // remember this is a view.  If you want a view of const data, make it
  // an array_view, not a const array_view.  It really works
  // out better.
private:
  T* b
  T* e;
};

the above sample code is not tested.