Allow expression weak references to be directly initialized from cwidget ref_ptrs.

1 files changed, 8 insertions, 0 deletions

diff --git a/src/generic/problemresolver/incremental_expression.h b/src/generic/problemresolver/incremental_expression.h
index 0456b95e..5c997e74 100644
--- a/src/generic/problemresolver/incremental_expression.h
+++ b/src/generic/problemresolver/incremental_expression.h
@@ -100,6 +100,7 @@ public:
   }
 
   expression_weak_ref(T *_expr);
+  expression_weak_ref(const cwidget::util::ref_ptr<T> &_expr);
 
   expression_weak_ref(const expression_weak_ref &other);
 
@@ -271,6 +272,13 @@ expression_weak_ref<T>::expression_weak_ref(T *_expr)
 }
 
 template<typename T>
+expression_weak_ref<T>::expression_weak_ref(const cwidget::util::ref_ptr<T> &_expr)
+  : expression_weak_ref_generic(true), expr(_expr.unsafe_get_ref())
+{
+  expr->add_weak_ref(this);
+}
+
+template<typename T>
 expression_weak_ref<T>::expression_weak_ref(const expression_weak_ref<T> &other)
   : expression_weak_ref_generic(other.get_valid()), expr(other.expr)
 {