ranges_views.cpp

Shows how to use xtd::ranges::views views.

#include <xtd/xtd>
 
auto main() -> int {
  //string names[] = {"Burke", "Connor", "Frank", "Everett", "Albert", "George", "Harris", "David"};
  //auto names = std::initializer_list {"Burke"_s, "Connor"_s, "Frank"_s, "Everett"_s, "Albert"_s, "George"_s, "Harris"_s, "David"_s};
  //auto names = std::array<string, 8> {"Burke", "Connor", "Frank", "Everett", "Albert", "George", "Harris", "David"};
  //auto names = std::vector {"Burke"_s, "Connor"_s, "Frank"_s, "Everett"_s, "Albert"_s, "George"_s, "Harris"_s, "David"_s};
  //auto names = std::list {"Burke"_s, "Connor"_s, "Frank"_s, "Everett"_s, "Albert"_s, "George"_s, "Harris"_s, "David"_s};
  //auto names = std::unordered_set {"Burke"_s, "Connor"_s, "Frank"_s, "Everett"_s, "Albert"_s, "George"_s, "Harris"_s, "David"_s};
  //auto names = fixed_array<string, 8> {"Burke", "Connor", "Frank", "Everett", "Albert", "George", "Harris", "David"};
  //auto names = array {"Burke"_s, "Connor"_s, "Frank"_s, "Everett"_s, "Albert"_s, "George"_s, "Harris"_s, "David"_s};
  //auto names = list {"Burke"_s, "Connor"_s, "Frank"_s, "Everett"_s, "Albert"_s, "George"_s, "Harris"_s, "David"_s};
  //auto names = linked_list {"Burke"_s, "Connor"_s, "Frank"_s, "Everett"_s, "Albert"_s, "George"_s, "Harris"_s, "David"_s};
  //auto names = hash_set {"Burke"_s, "Connor"_s, "Frank"_s, "Everett"_s, "Albert"_s, "George"_s, "Harris"_s, "David"_s};
  //auto names = queue {"Burke"_s, "Connor"_s, "Frank"_s, "Everett"_s, "Albert"_s, "George"_s, "Harris"_s, "David"_s};
  //auto names = stack {"Burke"_s, "Connor"_s, "Frank"_s, "Everett"_s, "Albert"_s, "George"_s, "Harris"_s, "David"_s};
  auto names = {"Burke"_s, "Connor"_s, "Frank"_s, "Everett"_s, "Albert"_s, "George"_s, "Harris"_s, "David"_s};
 
  // xtd::linq query
  auto query1 = from(names)
    .where(_*method(&string::length) == 5)
    .order_by(_)
    .select(_*method(&string::to_upper));
  println(query1);
  
  // xtd::ranges query
  auto query2 = names
    | where(_*method(&string::length) == 5)
    | order_by(_)
    | select(_*method(&string::to_upper));
  println(query2);
  
  // std::ranges combined with xtd::ranges query
  auto query3 = names
    | std::views::filter(_*method(&string::length) == 5)
    | xtd::views::order_by(_)
    | std::views::transform(_*method(&string::to_upper));
  println(query3);
}
 
// This code produces the following output :
//
// [BURKE, DAVID, FRANK]
// [BURKE, DAVID, FRANK]
// [BURKE, DAVID, FRANK]