CWG3148 Definition of "user-declared" special member function

Editorial note:
* In new wording from previous CWG3130, which added a new reference
  to "X" in [class.default.ctor], change "X" to "the class", since
  the change from CWG3148 removes the name "X".

Author: burblebee

source/classes.tex

@@ -580,6 +580,10 @@
 shall either
 declare at least one member name of the class
 or declare at least one unnamed bit-field.
+A \defnx{user-declared}{entity!user-declared}
+\indextext{user-declared entity|see{entity, user-declared}}
+entity is a direct member or a friend that, in either case,
+is declared by a \grammarterm{member-declaration}.
 
 \pnum
 A \defn{data member} is either a non-function member introduced by a
@@ -1273,8 +1277,9 @@
 has a default argument
 (including the case of a constructor with no parameters).
 \indextext{implicitly-declared default constructor}%
-If there is no user-declared constructor or constructor template for class
-\tcode{X} and \tcode{X} is not an anonymous union,
+If a class does not have
+a user-declared constructor or constructor template,
+and the class is not an anonymous union,
 a non-explicit constructor having no parameters is implicitly declared
 as defaulted\iref{dcl.fct.def}.
 An implicitly-declared default constructor is an
@@ -1503,7 +1508,7 @@
 \end{example}
 
 \pnum
-If the class definition does not explicitly declare a copy constructor
+If the class does not have a user-declared copy constructor
 and the class is not an anonymous union,
 a non-explicit one is declared \defnx{implicitly}{constructor!copy!implicitly declared}.
 If the class definition declares a move
@@ -1544,8 +1549,8 @@
 
 \pnum
 \indextext{constructor!move!implicitly declared}%
-If the definition of a class \tcode{X} does not explicitly declare
-a move constructor, a non-explicit one will be
+If a class \tcode{X} does not have
+a user-declared move constructor, a non-explicit one will be
 implicitly declared as defaulted if and only if
 \begin{itemize}
 \item
@@ -1605,6 +1610,17 @@
 an rvalue which can use the copy constructor instead.
 \end{note}
 
+\pnum
+\begin{note}
+A using-declaration in a derived class \tcode{C} that
+names a constructor from a base class
+never suppresses the implicit declaration of
+a copy/move constructor of \tcode{C},
+even if the base class constructor would be
+a copy or move constructor
+if declared as a member of \tcode{C}.
+\end{note}
+
 \pnum
 \indextext{constructor!copy!trivial}%
 \indextext{constructor!move!trivial}%
@@ -1746,10 +1762,10 @@
 \end{note}
 
 \pnum
-If the class definition does not explicitly declare a copy assignment operator
+If the class does not have a user-declared copy assignment operator
 and the class is not an anonymous union,
 one is declared \defnx{implicitly}{assignment operator!copy!implicitly declared}.
-If the class definition declares a move
+If the class has a user-declared move
 constructor or move assignment operator, the implicitly declared copy
 assignment operator is defined as deleted; otherwise, it is
 defaulted\iref{dcl.fct.def}.

source/declarations.tex

@@ -8803,14 +8803,14 @@
 \grammarterm{using-declaration} cannot refer to a
 destructor for a base class.
 \end{note}
-If a constructor or assignment operator brought from a base class into a derived class
-has the signature of a copy/move constructor or assignment operator
-for the derived class\iref{class.copy.ctor,class.copy.assign},
-the \grammarterm{using-declaration} does not by itself
-suppress the implicit declaration of the derived class member;
-the member from the base class is hidden or overridden
-by the implicitly-declared copy/move constructor or assignment operator
-of the derived class, as described below.
+\begin{note}
+A \grammarterm{using-declarator} that
+names a member function of a base class
+does not suppress the implicit declaration of a special member function
+in the derived class,
+even if their signatures are the
+same\iref{class.default.ctor, class.copy.ctor, class.copy.assign}.
+\end{note}
 
 \pnum
 A \grammarterm{using-declaration} shall not name a \grammarterm{template-id}.