update to version 6

Makefile

@@ -1,6 +1,6 @@
 CXXFLAGS:=-std=gnu++17 -Wall -O3 -MMD -MP -ggdb -pthread -fopenmp -Iext/flat_hash_map
 
-PROGRAMS = test exception smartfp string thread memory windex windex-par classes templates lambdas multi move
+PROGRAMS = test exception smartfp string thread memory windex windex-par classes templates lambdas multi move rest
 
 all: $(PROGRAMS)
 
@@ -40,3 +40,6 @@ multi: multi.o
 
 move: move.o 
 	g++ -std=gnu++17 $^ -o $@ -pthread 
+
+rest: rest.o 
+	g++ -std=gnu++17 $^ -o $@ -pthread 

multi.cc

@@ -24,10 +24,10 @@ std::ostream& operator<<(std::ostream& ios, const IPAddress& ip)
 
 constexpr uint32_t chtonl(uint32_t s)
 {
-    return (
+    return 
         ((s & 0x000000FF) << 24) | ((s & 0x0000FF00) << 8)
-      | ((s & 0xFF000000) >> 24) | ((s & 0x00FF0000) >> 8)
-    );
+      | ((s & 0xFF000000) >> 24) | ((s & 0x00FF0000) >> 8);
+
 }
 
 constexpr IPAddress operator "" _ipv4(const char* p, size_t l)

rest.cc

@@ -0,0 +1,145 @@
+#include <iostream>
+#include <limits>
+#include <fstream>
+#include <regex>
+#include <optional>
+
+using namespace std;
+
+struct Event
+{};
+
+struct Policy
+{
+  bool check() { return false; }
+}; 
+
+struct Channel
+{
+  enum class Priority { Low, Medium, High};
+  void sendEvent(const Event& e);
+  void sendEvent(const Event& e, Priority p);
+  void sendEvent2(const Event& e, std::optional<Priority> p={})
+  {
+    if(!p)
+      cout << "No priority passed" << endl;
+    switch(*p) {
+      case Priority::Low:
+        cout << "Low!" << endl; break;
+      case Priority::Medium:     
+        cout << "Medium!" << endl; break;      
+      case Priority::High:
+        cout << "High!" << endl; break;      
+      ;
+    }
+  }
+
+  std::optional<Policy> getPolicy(const Event& e)
+  {
+    return std::nullopt;
+  }
+};
+
+
+#include <type_traits>
+
+template<typename T>
+bool isSet(const T& t)
+{
+  static_assert(std::is_pointer<T>(), "isSet requires a pointer");
+  return t != nullptr;
+}
+
+int main(int argc, char** argv)
+{
+  static_assert(sizeof(int) == 4, "Int must be 4 bytes");
+
+  if(isSet(argv))
+    cout << "Yes, is set"<<endl;
+
+
+  int i;
+  cout << std::numeric_limits<int>::min() << endl;
+  cout << std::numeric_limits<decltype(i)>::max() << endl;
+
+  ifstream in("/etc/passwd");
+  if (!in.is_open()) {
+    std::cout << "failed to open\n";
+  } else {
+    string line;
+    int count = 0;
+    while(getline(in, line)) 
+      ++count;
+    cout << "Read " << count << " lines\n";
+  }
+
+  vector<int> vi{1, 2, 3, 4};
+  vector<string> vs{"foo", "bar", "baz"};
+
+  auto printAverages = [](int i){};
+
+  for(auto a : { 1, 10, 15} )
+    printAverages(a);
+
+  auto doAverage = [](vector<double> v) {};
+
+  vector<double> x, y, z;
+  for(auto& a : {x, y, z})
+    doAverage(a);
+
+  struct Coordinate
+  {
+        double x, y;
+  };
+
+
+  Coordinate coord{-1.0, 1.0};
+
+  auto [xc, yc] = coord;
+  xc = yc = 0;
+
+  std::string s = R"foo(Some people, when confronted with a problem, think: 
+"I know, I'll use regular expressions."
+Now they have two problems.)foo";
+
+  cout << s << endl;
+  std::regex word_regex("(\\S+)");
+  auto words_begin = 
+        std::sregex_iterator(s.begin(), s.end(), word_regex);
+  auto words_end = std::sregex_iterator();
+
+  std::cout << "Found "
+            << std::distance(words_begin, words_end)
+            << " words\n";
+
+  for_each(words_begin, words_end, [](const auto& w) {
+    cout << "Word: " << w.str() << endl;
+  });
+
+
+  Channel c;
+  Event e1, e2;
+
+  c.sendEvent2(e1);
+  c.sendEvent2(e2, Channel::Priority::High);
+
+  std::optional<Channel::Priority> p;
+  if(!p)
+    cout << "Priority not set" << endl;
+  p = Channel::Priority::High;
+  if(*p == Channel::Priority::High)
+    cout << "Priority is now set to High" << endl;
+
+  if(auto policy = c.getPolicy(e1)) {
+    if(policy->check())
+      c.sendEvent(e1);
+
+  }
+  else
+    cout << "No policy was set" <<endl;  
+
+  if(auto policy = c.getPolicy(e1); policy->check())
+    c.sendEvent(e1);
+
+}
+