CWG2356 Base class copy and move constructors should not be inherited

Author: jensmaurer

source/overloading.tex

@@ -630,8 +630,36 @@
 
 \pnum
 A defaulted move special function\iref{class.copy} that is
-defined as deleted is excluded from the set of candidate functions in all
-contexts.
+defined as deleted is excluded from the set of candidate functions
+in all contexts.
+A constructor inherited from class type \tcode{C}\iref{class.inhctor.init}
+that has a first parameter of type ``reference to \cvqual{cv1} \tcode{P}''
+(including such a constructor instantiated from a template)
+is excluded from the set of candidate functions
+when constructing an object of type \cvqual{cv2} \tcode{D}
+if the argument list has exactly one argument and
+\tcode{C} is reference-related to \tcode{P} and
+\tcode{P} is reference-related to \tcode{D}.
+\begin{example}
+\begin{codeblock}
+struct A {
+  A();
+  A(A &&);                              // \#1
+  template<typename T> A(T &&);         // \#2
+};
+struct B : A {
+  using A::A;
+  B(const B &);                         // \#3
+  B(B &&) = default;                    // \#4, implicitly deleted
+
+  struct X { X(X &&) = delete; } x;
+};
+extern B b1;
+B b2 = static_cast<B&&>(b1);            // calls \#3: \#1, \#2, and \#4 are not viable
+struct C { operator B&&(); };
+B b3 = C();                             // calls \#3
+\end{codeblock}
+\end{example}
 
 \rSec3[over.match.call]{Function call syntax}%
 \indextext{overloading!resolution!function call syntax|(}