Interoperability for Dispatch_output_iterator with variants, documentation and tests

STL_Extension/doc_tex/STL_Extension_ref/stl_extension.tex

@@ -203,8 +203,14 @@
   \ccCreationVariable{i}
 
   \ccDefinition The class \ccClassTemplateName\ defines an
-  \ccc{OutputIterator} that contains a tuple of output iterators, and dispatches
+  \ccc{OutputIterator} that contains a tuple of output iterators, and
-  among those based on the type of the value type which is put in it.
+  dispatches among those based on the type of the value type which is
+  put in it. Besides defining assignment for all parameters of V it is
+  also defined for the types \ccStyle{boost::variant<T\ldots>} and
+  \ccStyle{boost::optional<boost::variant<T\ldots>>}, where T\ldots\
+  must be a subset of the parameters of \ccc{V}. Should the
+  \ccStyle{boost::optional} be empty, it will be discarded.
+
   It also inherits from \ccc{O}, which makes it easy to treat like a tuple.
 
   \ccParameters
@@ -249,10 +255,17 @@
   \ccCreationVariable{i}
 
   \ccDefinition The class \ccClassTemplateName\ defines an
-  \ccc{OutputIterator} that contains a tuple of output iterators, and dispatches
+  \ccc{OutputIterator} that contains a tuple of output iterators, and
-  among those based on the type of the value type which is put in it.
+  dispatches among those based on the type of the value type which is
-  Other types are also accepted, and the object is simply discarded in this case.
+  put in it. Other types are also accepted, and the object is simply
-  It also inherits from \ccc{O}, which makes it easy to treat like a tuple.
+  discarded in this case. Besides defining assignment for all
+  parameters of V it is also defined for the types
+  \ccStyle{boost::variant<T\ldots>} and
+  \ccStyle{boost::optional<boost::variant<T\ldots>>}, where T\ldots\
+  can be a list of arbitrary types.
+
+  It also inherits from \ccc{O}, which makes it easy to treat like a
+  tuple.
 
   \ccParameters
   \ccc{V} must be a \ccc{CGAL::cpp0x::tuple<...>} of the types of values to be accepted and dispatched.

STL_Extension/include/CGAL/iterator.h

@@ -31,6 +31,8 @@
 #include <map>
 #include <boost/type_traits.hpp>
 #include <CGAL/tuple.h>
+#include <boost/variant.hpp>
+#include <boost/optional.hpp>
 
 #if defined(BOOST_MSVC)
 #  pragma warning(push)
@@ -1182,6 +1184,22 @@ inline Filter_output_iterator< I, P >
 filter_output_iterator(I e, const P& p)
 { return Filter_output_iterator< I, P >(e, p); }
 
+namespace internal {
+
+template<typename OutputIterator>
+struct Output_visitor : boost::static_visitor<OutputIterator&> {
+  Output_visitor(OutputIterator* it) : out(it) {}
+  OutputIterator* out;
+  
+  template<typename T>
+  OutputIterator& operator()(const T& t) {
+    *(*out)++ = t;
+    return *out;
+  }
+};
+
+} // internal
+
 
 #ifndef CGAL_CFG_NO_CPP0X_VARIADIC_TEMPLATES
 
@@ -1215,6 +1233,7 @@ struct Derivator<D, cpp0x::tuple<V1, V...>, cpp0x::tuple<O1, O...> >
     return static_cast<D&>(*this);
   }
 };
+};
 
 } // internal
 
@@ -1265,6 +1284,20 @@ public:
     return *this;
   }
 
+  template<BOOST_VARIANT_ENUM_PARAMS(typename T)>
+  Self& operator=(const boost::variant<BOOST_VARIANT_ENUM_PARAMS(T) >& t) {
+    internal::Output_visitor<Self> visitor(this);
+    boost::apply_visitor(visitor, t);
+    return *this;
+  }
+
+  template<BOOST_VARIANT_ENUM_PARAMS(typename T)>
+  Self& operator=(const boost::optional< boost::variant<BOOST_VARIANT_ENUM_PARAMS(T) > >& t) {
+    internal::Output_visitor<Self> visitor(this);
+    if(t) boost::apply_visitor(visitor, *t);
+    return *this;
+  }
+
   Self& operator++() { return *this; }
   Self& operator++(int) { return *this; }
   Self& operator*() { return *this; }
@@ -1366,6 +1399,20 @@ public:
     return *this;
   }
 
+  template<BOOST_VARIANT_ENUM_PARAMS(typename T)>
+  Self& operator=(const boost::variant<BOOST_VARIANT_ENUM_PARAMS(T) >& t) {
+    internal::Output_visitor<Self> visitor(this);
+    boost::apply_visitor(visitor, t);
+    return *this;
+  }
+
+  template<BOOST_VARIANT_ENUM_PARAMS(typename T)>
+  Self& operator=(const boost::optional< boost::variant<BOOST_VARIANT_ENUM_PARAMS(T) > >& t) {
+    internal::Output_visitor<Self> visitor(this);
+    if(t) boost::apply_visitor(visitor, *t);
+    return *this;
+  }
+  
   const Iterator_tuple& get_iterator_tuple() const
   { return *this; }
   
@@ -1467,6 +1514,20 @@ public:
     return *this;
   }
   
+  template<BOOST_VARIANT_ENUM_PARAMS(typename T)>
+  Self& operator=(const boost::variant<BOOST_VARIANT_ENUM_PARAMS(T) >& t) {
+    internal::Output_visitor<Self> visitor(this);
+    boost::apply_visitor(visitor, t);
+    return *this;
+  }
+
+  template<BOOST_VARIANT_ENUM_PARAMS(typename T)>
+  Self& operator=(const boost::optional< boost::variant<BOOST_VARIANT_ENUM_PARAMS(T) > >& t) {
+    internal::Output_visitor<Self> visitor(this);
+    if(t) boost::apply_visitor(visitor, *t);
+    return *this;
+  }
+
   const Iterator_tuple& get_iterator_tuple() const
   { return *this; }
   
@@ -1578,6 +1639,20 @@ public:
     return *this;
   }
   
+  template<BOOST_VARIANT_ENUM_PARAMS(typename T)>
+  Self& operator=(const boost::variant<BOOST_VARIANT_ENUM_PARAMS(T) >& t) {
+    internal::Output_visitor<Self> visitor(this);
+    boost::apply_visitor(visitor, t);
+    return *this;
+  }
+
+  template<BOOST_VARIANT_ENUM_PARAMS(typename T)>
+  Self& operator=(const boost::optional< boost::variant<BOOST_VARIANT_ENUM_PARAMS(T) > >& t) {
+    internal::Output_visitor<Self> visitor(this);
+    if(t) boost::apply_visitor(visitor, *t);
+    return *this;
+  }
+
   const Iterator_tuple& get_iterator_tuple() const
   { return *this; }
   
@@ -1702,6 +1777,20 @@ public:
     return *this;
   }
 
+  template<BOOST_VARIANT_ENUM_PARAMS(typename T)>
+  Self& operator=(const boost::variant<BOOST_VARIANT_ENUM_PARAMS(T) >& t) {
+    internal::Output_visitor<Self> visitor(this);
+    boost::apply_visitor(visitor, t);
+    return *this;
+  }
+
+  template<BOOST_VARIANT_ENUM_PARAMS(typename T)>
+  Self& operator=(const boost::optional< boost::variant<BOOST_VARIANT_ENUM_PARAMS(T) > >& t) {
+    internal::Output_visitor<Self> visitor(this);
+    if(t) boost::apply_visitor(visitor, *t);
+    return *this;
+  }
+
   const Iterator_tuple& get_iterator_tuple() const
   { return *this; }
   
@@ -1836,6 +1925,21 @@ public:
     return *this;
   }
   
+  template<BOOST_VARIANT_ENUM_PARAMS(typename T)>
+  Self& operator=(const boost::variant<BOOST_VARIANT_ENUM_PARAMS(T) >& t) {
+    internal::Output_visitor<Self> visitor(this);
+    boost::apply_visitor(visitor, t);
+    return *this;
+  }
+
+  template<BOOST_VARIANT_ENUM_PARAMS(typename T)>
+  Self& operator=(const boost::optional< boost::variant<BOOST_VARIANT_ENUM_PARAMS(T) > >& t) {
+    internal::Output_visitor<Self> visitor(this);
+    if(t) boost::apply_visitor(visitor, *t);
+    return *this;
+  }
+
+
   const Iterator_tuple& get_iterator_tuple() const
   { return *this; }
   
@@ -1980,6 +2084,20 @@ public:
     return *this;
   }
   
+  template<BOOST_VARIANT_ENUM_PARAMS(typename T)>
+  Self& operator=(const boost::variant<BOOST_VARIANT_ENUM_PARAMS(T) >& t) {
+    internal::Output_visitor<Self> visitor(this);
+    boost::apply_visitor(visitor, t);
+    return *this;
+  }
+
+  template<BOOST_VARIANT_ENUM_PARAMS(typename T)>
+  Self& operator=(const boost::optional< boost::variant<BOOST_VARIANT_ENUM_PARAMS(T) > >& t) {
+    internal::Output_visitor<Self> visitor(this);
+    if(t) boost::apply_visitor(visitor, *t);
+    return *this;
+  }
+
   const Iterator_tuple& get_iterator_tuple() const
   { return *this; }
   
@@ -2134,6 +2252,20 @@ public:
     return *this;
   }
   
+  template<BOOST_VARIANT_ENUM_PARAMS(typename T)>
+  Self& operator=(const boost::variant<BOOST_VARIANT_ENUM_PARAMS(T) >& t) {
+    internal::Output_visitor<Self> visitor(this);
+    boost::apply_visitor(visitor, t);
+    return *this;
+  }
+
+  template<BOOST_VARIANT_ENUM_PARAMS(typename T)>
+  Self& operator=(const boost::optional< boost::variant<BOOST_VARIANT_ENUM_PARAMS(T) > >& t) {
+    internal::Output_visitor<Self> visitor(this);
+    if(t) boost::apply_visitor(visitor, *t);
+    return *this;
+  }
+
   const Iterator_tuple& get_iterator_tuple() const
   { return *this; }
   

STL_Extension/test/STL_Extension/test_dispatch_output.cpp

@@ -6,6 +6,9 @@
 
 #include <CGAL/iterator.h>
 
+#include <boost/variant.hpp>
+#include <boost/optional.hpp>
+
 struct A{};
 struct B{};
 
@@ -76,6 +79,47 @@ void complete_test(std::vector<T1> data1,std::list<T2> data2){
 	CGAL::cpp0x::tie(d, bck_ins) = drop;
 }
 
+void variant_test() {
+  typedef boost::variant<int, char, double> var;
+  typedef boost::optional< var > ovar;
+  std::vector<int> a;
+  std::vector<double> b;
+  std::vector<char> c;
+  typedef CGAL::Dispatch_output_iterator< 
+    CGAL::cpp0x::tuple<int, double, char>,
+    CGAL::cpp0x::tuple<std::back_insert_iterator< std::vector<int> >,
+                       std::back_insert_iterator< std::vector<double> >,
+                       std::back_insert_iterator< std::vector<char> > 
+                       > > Dispatch;
+  Dispatch disp = CGAL::dispatch_output<int, double, char>(std::back_inserter(a),
+                                                           std::back_inserter(b),
+                                                           std::back_inserter(c));
+  {
+    var va = 23; var vb = 4.2; var vc = 'x';
+    *disp++ = va; *disp++ = vb; *disp++ = vc; *disp++ = 42;
+  }
+  assert(a.size() == 2);
+  assert(a.front() == 23);
+  assert(a.back() == 42);
+  assert(b.size() == 1);
+  assert(b.front() == 4.2);
+  assert(c.size() == 1);
+  assert(c.front() == 'x');
+  a.clear(); b.clear(); c.clear();
+
+  {
+    ovar va = var(23); ovar vb = var(4.2); ovar vc = var('x');
+    *disp++ = va; *disp++ = vb; *disp++ = vc; *disp++ = 42; *disp++ = ovar();
+  }
+  assert(a.size() == 2);
+  assert(a.front() == 23);
+  assert(a.back() == 42);
+  assert(b.size() == 1);
+  assert(b.front() == 4.2);
+  assert(c.size() == 1);
+  assert(c.front() == 'x');
+}
+
 
 int main(){
   std::list<int> list1;
@@ -93,5 +137,7 @@ int main(){
   complete_test(vect2,list1);
   complete_test(vect2,list2);
   
+  variant_test();
+
   return 0;
 }