Make two programs less verbose

Fix #6353

Mesh_3/include/CGAL/Mesh_3/Mesh_global_optimizer.h

@@ -975,7 +975,7 @@ update_mesh(const Moves_vector& moves,
         FT size = std::get<2>(*it);
 
 #ifdef CGAL_MESH_3_OPTIMIZER_VERBOSE
-        std::cout << "Moving #" << it - moves.begin()
+        std::cerr << "Moving #" << it - moves.begin()
                   << " addr: " << &*v
                   << " pt: " << tr_.point(v)
                   << " move: " << move << std::endl;

Mesh_3/test/Mesh_3/test_meshing_polyhedron_with_features.cpp

@@ -23,10 +23,56 @@
 #include <CGAL/use.h>
 
 #include <fstream>
+#include <sstream>
+
+static constexpr bool verbose =
+#if CGAL_MESH_3_VERBOSE
+  true;
+#else
+  false;
+#endif
+
+
+std::stringstream cerr_output;
 
 template <typename K, typename Concurrency_tag = CGAL::Sequential_tag>
 struct Polyhedron_with_features_tester : public Tester<K>
 {
+  std::streambuf* old_cerr_buf;
+  std::string tag_name;
+
+  Polyhedron_with_features_tester(std::string tag_name)
+    : old_cerr_buf(std::cerr.rdbuf(verbose ? cerr_output.rdbuf() : std::cerr.rdbuf()))
+    , tag_name(tag_name)
+  {
+  }
+  ~Polyhedron_with_features_tester()
+  {
+    std::cerr.rdbuf(old_cerr_buf);
+    if(verbose) {
+      const auto output = cerr_output.str();
+      const auto str_size= output.size();
+      const auto str_begin = output.data();
+      const auto str_end = str_begin + str_size;
+      constexpr auto nb = static_cast<decltype(str_size)>(10000);
+      auto pos1 = str_begin + (std::min)(nb, str_size);
+      assert(pos1 <= str_end);
+      const auto pos2 = str_end - (std::min)(nb, str_size);
+      assert(pos2 >= str_begin);
+      if(pos2 <= pos1) {
+        pos1 = str_end;
+      }
+      std::cerr << "NOW THE FIRST AND LAST 10k CHARACTERS OF THE CERR OUTPUT:\n";
+      std::cerr << "-----\n" << std::string(str_begin, pos1) << "\n-----\n";
+      if(pos1 != str_end) {
+        std::cerr << "[...]\n-----\n" << std::string(pos2, str_end) << "\n-----\n";
+      }
+      const auto file_name = std::string("test_meshing_verbose-") + tag_name + ".txt";
+      std::ofstream file_output(file_name);
+      file_output << output;
+      std::cerr << "Full log is output to " << file_name << "\n";
+    }
+  }
   void operator()() const
   {
     typedef CGAL::Mesh_3::Robust_intersection_traits_3<K> Gt;
@@ -107,14 +153,17 @@ struct Polyhedron_with_features_tester : public Tester<K>
 
 int main()
 {
-  Polyhedron_with_features_tester<K_e_i> test_epic;
+  {
-  std::cerr << "Mesh generation from a polyhedron with edges:\n";
+    std::cerr << "Mesh generation from a polyhedron with edges:\n";
-  test_epic();
+    Polyhedron_with_features_tester<K_e_i> test_epic("sequential");
-
+    test_epic();
+  }
 #ifdef CGAL_LINKED_WITH_TBB
-  Polyhedron_with_features_tester<K_e_i, CGAL::Parallel_tag> test_epic_p;
+  {
-  std::cerr << "Parallel mesh generation from a polyhedron with edges:\n";
+    std::cerr << "Parallel mesh generation from a polyhedron with edges:\n";
-  test_epic_p();
+    Polyhedron_with_features_tester<K_e_i, CGAL::Parallel_tag> test_epic_p("parallel");
+    test_epic_p();
+  }
 #endif
 
   return EXIT_SUCCESS;

Voronoi_diagram_2/test/Voronoi_diagram_2/vda_tos2.cpp

@@ -10,6 +10,7 @@
 #include <iostream>
 #include <iterator>
 #include <fstream>
+#include <sstream>
 #include <vector>
 
 typedef CGAL::Exact_predicates_inexact_constructions_kernel K;
@@ -170,6 +171,10 @@ int main(int argc, char** argv)
   std::cout << vd.number_of_faces() << " faces" << std::endl;
   std::cout << "dimension = " << vd.dual().dimension() << std::endl;
 
+  // redirect std::cout to cout_output
+  std::stringstream cout_output;
+  std::streambuf* old_cout_buf = std::cout.rdbuf(cout_output.rdbuf());
+
   VD::Vertex_iterator vit = vd.vertices_begin(), vend = vd.vertices_end();
   for(; vit!=vend; ++vit)
   {
@@ -197,5 +202,29 @@ int main(int argc, char** argv)
     CGAL_USE(opposite_h);
   }
 
+  // now restore std::cout and display the output
+  std::cout.rdbuf(old_cout_buf);
+  const auto output = cout_output.str();
+  const auto str_size = output.size();
+  const auto str_begin = output.data();
+  const auto str_end = str_begin + str_size;
+  constexpr auto nb = static_cast<decltype(str_size)>(10000);
+  auto pos1 = str_begin + (std::min)(nb, str_size);
+  assert(pos1 <= str_end);
+  const auto pos2 = str_end - (std::min)(nb, str_size);
+  assert(pos2 >= str_begin);
+  if (pos2 <= pos1) {
+    pos1 = str_end;
+  }
+  std::cout << "NOW THE FIRST AND LAST 10k CHARACTERS OF THE COUT OUTPUT:\n";
+  std::cout << "-----\n" << std::string(str_begin, pos1) << "\n-----\n";
+  if (pos1 != str_end) {
+    std::cout << "[...]\n-----\n" << std::string(pos2, str_end) << "\n-----\n";
+  }
+  const auto file_name = "vda_tos2_test_output.txt";
+  std::ofstream file_output(file_name);
+  file_output << output;
+  std::cout << "Full log is output to " << file_name << "\n";
+
   return EXIT_SUCCESS;
 }