Merge pull request #38 from nliber/issue260

Rule of Zero for Common by-value semantics classes (Gitlab issue 260)

Author: keryell

latex/glossary.tex

@@ -445,6 +445,26 @@
   )}
 }
 
+\newglossaryentry{rule-of-five}
+{
+  name={rule of five},
+  description={For a given class, if at least one of the
+  copy constructor, move constructor, copy assignment operator, move assignment operator or destructor
+  is explicitly declared,
+  all of them should be explicity declared
+  }
+}
+
+\newglossaryentry{rule-of-zero}
+{
+  name={rule of zero},
+  description={For a given class, if the
+  copy constructor, move constructor, copy assignment operator, move assignment operator and destructor
+  would all be inlined, public and defaulted,
+  none of them should be explicity declared
+  }
+}
+
 \newglossaryentry{smcp}
 {
   name={SMCP},

latex/headers/common-byval.h

@@ -19,15 +19,21 @@ class T {
   ...
 
  public:
-  T(const T &rhs) = default;
+  // If any of the following five special member functions are not
+  // public, inline or defaulted, then all five of them should be
+  // explicitly declared (see rule of five).
+  // Otherwise, none of them should be explicitly declared
+  // (see rule of zero).
 
-  T(T &&rhs) = default;
+  // T(const T &rhs);
 
-  T &operator=(const T &rhs) = default;
+  // T(T &&rhs);
 
-  T &operator=(T &&rhs) = default;
+  // T &operator=(const T &rhs);
 
-  ~T() = default;
+  // T &operator=(T &&rhs);
+
+  // ~T();
 
   ...
 

latex/programming_interface.tex

@@ -187,39 +187,39 @@ \subsection{Common by-value semantics}
 
 Some \gls{sycl-runtime} classes will have additional behavior associated with copy, movement, assignment or destruction semantics. If these are specified they are in addition to those specified above unless stated otherwise.
 
-Each of the runtime classes mentioned above must provide a common interface of special member functions in order to fulfil the copy, move, destruction requirements and hidden friend functions to satisfy the equality requirements.
+Each of the runtime classes mentioned above must provide a common interface of special member functions and member functions in order to fulfil the copy, move, destruction and equality requirements, following the \gls{rule-of-five} and the \gls{rule-of-zero}.
 
 These common special member functions and hidden friend functions are described in Tables~\ref{table.specialmembers.common.byval} and \ref{table.hiddenfriends.common.byval} respectively.
 
 \lstinputlistingSkipLicense{headers/common-byval.h}
 
-\startTable{Special member function}
+\startTable{Special member function \textit{(see \gls{rule-of-five} \& \gls{rule-of-zero})}}
 \addFootNotes{Common special member functions for by-value semantics}
 {table.specialmembers.common.byval}
   \addRow
-    {T(const T \&rhs) = default}
+    {T(const T \&rhs);}
     {
-      Default copy constructor.  
+      Copy constructor.
     }
   \addRow
-    {T(T \&\&rhs) = default}
+    {T(T \&\&rhs);}
     {
-      Default move constructor.
+      Move constructor.
     }  
    \addRow
-   {T \&operator=(const T \&rhs) = default}
+   {T \&operator=(const T \&rhs);}
    {
-     Default copy assignment operator.
+     Copy assignment operator.
    }
    \addRow
-   {T \&operator=(T \&\&rhs) = default}
+   {T \&operator=(T \&\&rhs);}
    {
-     Default move assignment operator.
+     Move assignment operator.
    }
    \addRow
-   {\~T() = default}
+   {\~T();}
    {
-     Default destructor.
+     Destructor.
    }
 \completeTable