2 files changed, 28 insertions, 3 deletions
diff --git a/include/experimental/coroutine b/include/experimental/coroutine
index d2a03ae8a8c8..21c1ea566403 100644
--- a/include/experimental/coroutine
+++ b/include/experimental/coroutine
@@ -145,6 +145,19 @@ public:
         return __tmp;
     }
 
+    // FIXME: Should from_address(nullptr) be allowed?
+    _LIBCPP_ALWAYS_INLINE
+    static coroutine_handle from_address(nullptr_t) _NOEXCEPT {
+      return coroutine_handle(nullptr);
+    }
+
+    template <class _Tp, bool _CallIsValid = false>
+    static coroutine_handle from_address(_Tp*) {
+      static_assert(_CallIsValid,
+       "coroutine_handle<void>::from_address cannot be called with "
+        "non-void pointers");
+    }
+
 private:
   bool __is_suspended() const _NOEXCEPT  {
     // FIXME actually implement a check for if the coro is suspended.
@@ -218,11 +231,22 @@ public:
     // FIXME: should from_address work with nullptr?
     _LIBCPP_ALWAYS_INLINE
     static coroutine_handle from_address(nullptr_t) _NOEXCEPT {
-      return {};
+      return coroutine_handle(nullptr);
+    }
+
+    template <class _Tp, bool _CallIsValid = false>
+    static coroutine_handle from_address(_Tp*) {
+      static_assert(_CallIsValid,
+       "coroutine_handle<promise_type>::from_address cannot be called with "
+        "non-void pointers");
     }
 
-    // from_address cannot be used with the coroutines promise type.
-    static coroutine_handle from_address(_Promise*) = delete;
+    template <bool _CallIsValid = false>
+    static coroutine_handle from_address(_Promise*) {
+      static_assert(_CallIsValid,
+       "coroutine_handle<promise_type>::from_address cannot be used with "
+        "pointers to the coroutine's promise type; use 'from_promise' instead");
+    }
 
     _LIBCPP_ALWAYS_INLINE
     static coroutine_handle from_promise(_Promise& __promise) _NOEXCEPT {
diff --git a/include/module.modulemap b/include/module.modulemap
index 462d4234ae6c..98b1870afcc1 100644
--- a/include/module.modulemap
+++ b/include/module.modulemap
@@ -502,6 +502,7 @@ module std [system] {
       export *
     }
      module coroutine {
+      requires coroutines
       header "experimental/coroutine"
       export *
     }