Force use of C++17

Routing use c++17 features (e.g. structured binding)
ref: https://en.cppreference.com/w/cpp/language/structured_binding

examples/cpp/CMakeLists.txt

@@ -54,7 +54,7 @@ foreach(EXECUTABLE
   weighted_tardiness_sat)
   add_executable(${EXECUTABLE} ${EXECUTABLE}.cc)
   target_include_directories(${EXECUTABLE} PUBLIC ${PARENT_SOURCE_DIR})
-  target_compile_features(${EXECUTABLE} PRIVATE cxx_std_11)
+  target_compile_features(${EXECUTABLE} PRIVATE cxx_std_17)
   target_link_libraries(${EXECUTABLE} PRIVATE ortools::ortools)
   set_target_properties(${EXECUTABLE} PROPERTIES
     INSTALL_RPATH_USE_LINK_PATH TRUE)