where_view.hpp

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#pragma once
 
#define __XTD_STD_INTERNAL__
#include "../../internal/__xtd_std_version.hpp"
#undef __XTD_STD_INTERNAL__
#include "../../linq/enumerable.hpp"
#include "../../istringable.hpp"
#include "../../string.hpp"
#include "../../views/views.hpp"

#if defined(__xtd__cpp_lib_ranges)
#include <ranges>

namespace xtd {
  namespace ranges {
    namespace views {
      class where_view {
        template <typename predicate_t>
        struct with_predicate {
          const predicate_t& predicate;
          
          template <std::ranges::range range_t>
          auto operator()(range_t&& source) const {return xtd::linq::enumerable::as_enumerable(std::forward<range_t>(source)).where(predicate);}
          
          template <std::ranges::range range_t>
          friend auto operator |(range_t&& source, const with_predicate& self) {return self(std::forward<range_t>(source));}
        };
        
      public:
        
        template <std::ranges::range range_t, typename predicate_t>
        auto operator()(range_t&& source, const predicate_t& predicate) const {return xtd::linq::enumerable::from(std::forward<range_t>(source)).where(predicate);}
        template <typename predicate_t>
        auto operator()(const predicate_t& predicate) const {return with_predicate {predicate};}
        
        template <std::ranges::range range_type>
        friend auto operator |(range_type&& source, const where_view& view) {return view(std::forward<range_type>(source));}
      };
    }
  }
}
#endif