text: //===----------------------------------------------------------------------===//
  //
  // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
  // See https://llvm.org/LICENSE.txt for license information.
  // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
  //
  //===----------------------------------------------------------------------===//
  
  // <functional>
  // REQUIRES: c++98 || c++03 || c++11 || c++14
  
  // template <class Fn>
  // class binder2nd
  //   : public unary_function<typename Fn::first_argument_type, typename Fn::result_type>
  // {
  // protected:
  //   Fn op;
  //   typename Fn::second_argument_type value;
  // public:
  //   binder2nd(const Fn& x, const typename Fn::second_argument_type& y);
  //
  //   typename Fn::result_type operator()(const typename Fn::first_argument_type& x) const;
  //   typename Fn::result_type operator()(typename Fn::first_argument_type& x) const;
  // };
  
  #define _LIBCPP_DISABLE_DEPRECATION_WARNINGS
  
  #include <functional>
  #include <type_traits>
  #include <cassert>
  
  #include "test_macros.h"
  #include "../test_func.h"
  
  class test
      : public std::binder2nd<test_func>
  {
      typedef std::binder2nd<test_func> base;
  public:
      test() : std::binder2nd<test_func>(test_func(3), 4.5) {}
  
      void do_test()
      {
          static_assert((std::is_base_of<
                           std::unary_function<test_func::first_argument_type,
                                               test_func::result_type>,
                           test>::value), "");
          assert(op.id() == 3);
          assert(value == 4.5);
  
          int i = 5;
          assert((*this)(i) == 22.5);
          assert((*this)(5) == 0.5);
      }
  };
  
  int main(int, char**)
  {
      test t;
      t.do_test();
  
    return 0;
  }
  