compile unit tests with C++20

Author: pfeatherstone

examples/CMakeLists.txt

@@ -49,6 +49,7 @@ add_executable(tests
   unit_tests/sha1.cpp
   unit_tests/message.cpp
   unit_tests/async.cpp)
+target_compile_features(tests PUBLIC cxx_std_20)
 target_link_options(tests PRIVATE $<$<CONFIG:Release>:-s>)
 target_include_directories(tests PRIVATE ${CMAKE_CURRENT_SOURCE_DIR}/extra)
 target_link_libraries(tests PRIVATE http)