Vendor import of libc++ trunk r304460:vendor/libc++/libc++-trunk-r304460

https://llvm.org/svn/llvm-project/libcxx/trunk@304460

1 files changed, 83 insertions, 0 deletions

diff --git a/test/std/experimental/language.support/support.coroutines/end.to.end/oneshot_func.pass.cpp b/test/std/experimental/language.support/support.coroutines/end.to.end/oneshot_func.pass.cpp
new file mode 100644
index 000000000000..d5f2c40e2a79
--- /dev/null
+++ b/test/std/experimental/language.support/support.coroutines/end.to.end/oneshot_func.pass.cpp
@@ -0,0 +1,83 @@
+// -*- C++ -*-
+//===----------------------------------------------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is dual licensed under the MIT and the University of Illinois Open
+// Source Licenses. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+// UNSUPPORTED: c++98, c++03, c++11
+
+#include <experimental/coroutine>
+#include <vector>
+#include <cassert>
+
+using namespace std::experimental;
+
+// This file tests, one shot, movable std::function like thing using coroutine
+// for compile-time type erasure and unerasure.
+
+template <typename R> struct func {
+  struct promise_type {
+    R result;
+    func get_return_object() { return {this}; }
+    suspend_always initial_suspend() { return {}; }
+    suspend_always final_suspend() { return {}; }
+    void return_value(R v) { result = v; }
+    void unhandled_exception() {}
+  };
+
+  R operator()() {
+    h.resume();
+    R result = h.promise().result;
+    h.destroy();
+    h = nullptr;
+    return result;
+  };
+
+  func() {}
+  func(func &&rhs) : h(rhs.h) { rhs.h = nullptr; }
+  func(func const &) = delete;
+
+  func &operator=(func &&rhs) {
+    if (this != &rhs) {
+      if (h)
+        h.destroy();
+      h = rhs.h;
+      rhs.h = nullptr;
+    }
+    return *this;
+  }
+
+  template <typename F> static func Create(F f) { co_return f(); }
+
+  template <typename F> func(F f) : func(Create(f)) {}
+
+  ~func() {
+    if (h)
+      h.destroy();
+  }
+
+private:
+  func(promise_type *promise)
+      : h(coroutine_handle<promise_type>::from_promise(*promise)) {}
+  coroutine_handle<promise_type> h;
+};
+
+std::vector<int> yielded_values = {};
+int yield(int x) { yielded_values.push_back(x); return x + 1; }
+float fyield(int x) { yielded_values.push_back(x); return x + 2; }
+
+void Do1(func<int> f) { yield(f()); }
+void Do2(func<double> f) { yield(f()); }
+
+int main() {
+  Do1([] { return yield(43); });
+  assert((yielded_values == std::vector<int>{43, 44}));
+
+  yielded_values = {};
+  Do2([] { return fyield(44); });
+  assert((yielded_values == std::vector<int>{44, 46}));
+}