Made compatible with C++11. No need for C++14 requirement if only usi…

…ng chrono_literals from it.

CMakeLists.txt

@@ -1,7 +1,7 @@
 cmake_minimum_required(VERSION 3.7)
 project(BosmaScheduler)
 
-set(CMAKE_CXX_STANDARD 14)
+set(CMAKE_CXX_STANDARD 11)
 
 # threads
 set(THREADS_PREFER_PTHREAD_FLAG ON)

Cron.h

@@ -6,7 +6,6 @@
 
 namespace Bosma {
   using Clock = std::chrono::system_clock;
-  using namespace std::chrono_literals;
 
   inline void add(std::tm &tm, std::chrono::nanoseconds time) {
     auto tp = Clock::from_time_t(std::mktime(&tm));

Scheduler.h

@@ -29,7 +29,7 @@ namespace Bosma {
     explicit InTask(std::function<void()> &&f) : Task(std::move(f)) {}
 
     // dummy time_point because it's not used
-    Clock::time_point get_new_time() const override { return Clock::time_point(0ns); }
+    Clock::time_point get_new_time() const override { return Clock::time_point(std::chrono::nanoseconds(0)); }
   };
 
   class EveryTask : public Task {

example.cpp

@@ -2,8 +2,6 @@
 
 #include "Scheduler.h"
 
-using namespace std::chrono_literals;
-
 void message(const std::string &s) {
   std::cout << s << std::endl;
 }
@@ -19,15 +17,15 @@ int main() {
   Bosma::Scheduler s(max_n_threads);
 
   // every second call message("every second")
-  s.every(1s, message, "every second");
+  s.every(std::chrono::seconds(1), message, "every second");
 
   // in one minute
-  s.in(1min, []() { std::cout << "in one minute" << std::endl; });
+  s.in(std::chrono::minutes(1), []() { std::cout << "in one minute" << std::endl; });
 
   // in one second run lambda, then wait a second, run lambda, and so on
   // different from every in that multiple instances of the function will not be run concurrently
-  s.interval(1s, []() {
-    std::this_thread::sleep_for(5s);
+  s.interval(std::chrono::seconds(1), []() {
+    std::this_thread::sleep_for(std::chrono::seconds(5));
     std::cout << "once every 6s" << std::endl;
   });
 
@@ -43,5 +41,5 @@ int main() {
   s.cron("5 0 * * *", []() { std::cout << "every day 5 minutes after midnight" << std::endl; });
 
   // destructor of Bosma::Scheduler will cancel all schedules but finish any tasks currently running
-  std::this_thread::sleep_for(30min);
+  std::this_thread::sleep_for(std::chrono::minutes(10));
 }