Use c++20 for standalone build

Author: dirkvdb

CMakeLists.txt

@@ -35,7 +35,7 @@ if(INFRA_IS_TOPLEVEL)
     cmake_minimum_required(VERSION 3.21)
 
     if(NOT CMAKE_CXX_STANDARD)
-        set(CMAKE_CXX_STANDARD 17)
+        set(CMAKE_CXX_STANDARD 20)
     endif()
 
     if(INFRA_ENABLE_TESTS)

test/chronotest.cpp

@@ -4,18 +4,18 @@
 
 namespace inf::test {
 
-using namespace date;
+using namespace std::chrono_literals;
 
 TEST_CASE("ChronoTest.time_point_to_utc_string")
 {
-    chrono::date_point date = 2017_y / feb / 1;
+    chrono::date_point date = 2017y / std::chrono::February / 1;
 
     CHECK("2017-02-01" == inf::chrono::to_string("%Y-%m-%d", date));
 }
 
 TEST_CASE("ChronoTest.time_point_to_string_custom_format")
 {
-    chrono::date_point date = 2017_y / feb / 1;
+    chrono::date_point date = 2017y / std::chrono::February / 1;
 
     CHECK("2017-02-01" == inf::chrono::to_string("%Y-%m-%d", date));
     CHECK("2017-01-02" == inf::chrono::to_string("%Y-%d-%m", date));