1  #if __has_include(<coroutine>)
       2  
       3  #include <coroutine>
       4  
       5  namespace coro = std;
       6  
       7  #elif __has_include(<experimental/coroutine>)
       8  
       9  #include <experimental/coroutine>
      10  
      11  namespace coro = std::experimental;
      12  
      13  #else
      14  
      15  #warning "no installed coroutine headers found, using test-suite local one"
      16  
      17  /* Dummy version to allow tests without an installed header.  */
      18  #  ifndef __TESTSUITE_CORO_H_n4835
      19  #  define __TESTSUITE_CORO_H_n4835
      20  
      21  // Fragments (with short-cuts) to mimic enough of the library header to
      22  // make some progress.
      23  
      24  #  if __cpp_impl_coroutine
      25  
      26  namespace std {
      27  inline namespace __n4861 {
      28  
      29  // 21.11.1 coroutine traits
      30  template<typename _R, typename...> struct coroutine_traits {
      31    using promise_type = typename _R::promise_type;
      32  };
      33  
      34  // 21.11.2  coroutine handle
      35  template <typename Promise = void> struct coroutine_handle;
      36  
      37  template <> 
      38  struct coroutine_handle<void> {
      39    public:
      40        // 21.11.2.1 construct/reset
      41    constexpr coroutine_handle () noexcept
      42      : __fr_ptr (0) {}
      43    constexpr coroutine_handle (decltype(nullptr) __h) noexcept
      44      : __fr_ptr (__h) {}
      45    coroutine_handle &operator= (decltype(nullptr)) noexcept {
      46      __fr_ptr = nullptr;
      47      return *this;
      48    }
      49  
      50    public:
      51      // 21.11.2.2 export/import
      52      constexpr void *address () const noexcept { return __fr_ptr; }
      53      constexpr static coroutine_handle from_address (void *__a) noexcept {
      54        coroutine_handle __self;
      55        __self.__fr_ptr = __a;
      56        return __self;
      57      }
      58    public:
      59        // 21.11.2.3 observers
      60      constexpr explicit operator bool () const noexcept {
      61        return bool (__fr_ptr);
      62      }
      63      bool done () const noexcept {
      64        return __builtin_coro_done (__fr_ptr);
      65      }
      66        // 21.11.2.4 resumption
      67      void operator () () const { resume (); }
      68      void resume () const {
      69        __builtin_coro_resume (__fr_ptr);
      70      }
      71      void destroy () const {
      72        __builtin_coro_destroy (__fr_ptr);
      73      }
      74    protected:
      75      void *__fr_ptr;
      76  };
      77  
      78  template <class _Promise>
      79  struct coroutine_handle : coroutine_handle<> {
      80    // 21.11.2.1 construct/reset
      81    using coroutine_handle<>::coroutine_handle;
      82    static coroutine_handle from_promise(_Promise &p) {
      83      coroutine_handle __self;
      84      __self.__fr_ptr = 
      85        __builtin_coro_promise((char *)&p,  __alignof(_Promise), true);
      86      return __self;
      87    }
      88    coroutine_handle& operator=(decltype(nullptr)) noexcept {
      89      coroutine_handle<>::operator=(nullptr);
      90      return *this;
      91    }
      92    // 21.11.2.2 export/import
      93    constexpr static coroutine_handle from_address(void* __a){
      94      coroutine_handle __self;
      95      __self.__fr_ptr = __a;
      96      return __self;
      97    }
      98    // 21.11.2.5 promise access
      99    _Promise& promise() const {
     100      void * __t = __builtin_coro_promise(this->__fr_ptr,
     101  					__alignof(_Promise), false);
     102      return *static_cast<_Promise*>(__t);
     103    }
     104  };
     105  
     106  // n4760 - 21.11.5 trivial awaitables
     107  
     108  struct suspend_always {
     109    bool await_ready() { return false; }
     110    void await_suspend(coroutine_handle<>) {}
     111    void await_resume() {}
     112  };
     113  
     114  struct suspend_never {
     115    bool await_ready() { return true; }
     116    void await_suspend(coroutine_handle<>) {}
     117    void await_resume() {}
     118  };
     119  
     120  } // namespace __n4861
     121  } // namespace std
     122  
     123  namespace coro = std;
     124  
     125  #  else
     126  #    error "coro.h requires support for coroutines, add -fcoroutines"
     127  #  endif
     128  #  endif // __TESTSUITE_CORO_H_n4835
     129  
     130  #endif // __has_include(<experimental/coroutine>)
     131  
     132  #include <cstdlib> /* for abort () */
     133  
     134  #include <utility> /* for std::forward */
     135  
     136  #ifndef OUTPUT
     137  #  define PRINT(X)
     138  #  define PRINTF (void)
     139  #else
     140  #include <stdio.h>
     141  #  define PRINT(X) puts(X)
     142  #  define PRINTF printf
     143  #endif