Sadly, one of the spelling mistakes hid a warning message... @mschimek Is that your code?
[50/193] Building CXX object examples/applications/CMakeFiles/sample_sort.dir/sample-sort/sample_sort.cpp.o
In file included from /home/lukas/projects/kamping/examples/applications/sample-sort/sample_sort.cpp:20:
/home/lukas/projects/kamping/include/kamping/measurements/printer.hpp: In member function ‘void kamping::measurements::SimpleJsonPrinter<Duration>::print(const kamping::measurements::AggregatedTreeNode<Duration>&, std::size_t)’:
/home/lukas/projects/kamping/include/kamping/measurements/printer.hpp:83:51: warning: declaration of ‘_internal_printer’ shadows a member of ‘kamping::measurements::SimpleJsonPrinter<Duration>’ [-Wshadow]
83 | internal::ScalarOrVectorPrinter<Duration> _internal_printer{_outstream};
| ^~~~~~~~~~~~~~~~~
/home/lukas/projects/kamping/include/kamping/measurements/printer.hpp:131:9: note: shadowed declaration is here
131 | _internal_printer; ///< Internal printer able to print either a scalar or vector of durations.
| ^~~~~~~~~~~~~~~~~
[53/193] Building CXX object examples/usage/CMakeFiles/example_timer.dir/timer_example.cpp.o
In file included from /home/lukas/projects/kamping/examples/usage/timer_example.cpp:29:
/home/lukas/projects/kamping/include/kamping/measurements/printer.hpp: In member function ‘void kamping::measurements::SimpleJsonPrinter<Duration>::print(const kamping::measurements::AggregatedTreeNode<Duration>&, std::size_t)’:
/home/lukas/projects/kamping/include/kamping/measurements/printer.hpp:83:51: warning: declaration of ‘_internal_printer’ shadows a member of ‘kamping::measurements::SimpleJsonPrinter<Duration>’ [-Wshadow]
83 | internal::ScalarOrVectorPrinter<Duration> _internal_printer{_outstream};
| ^~~~~~~~~~~~~~~~~
/home/lukas/projects/kamping/include/kamping/measurements/printer.hpp:131:9: note: shadowed declaration is here
131 | _internal_printer; ///< Internal printer able to print either a scalar or vector of durations.
| ^~~~~~~~~~~~~~~~~
/home/lukas/projects/kamping/include/kamping/measurements/printer.hpp: In instantiation of ‘void kamping::measurements::SimpleJsonPrinter<Duration>::print(const kamping::measurements::AggregatedTreeNode<Duration>&, std::size_t) [with Duration = double; std::size_t = long unsigned int]’:
/home/lukas/projects/kamping/include/kamping/measurements/timer.hpp:217:26: required from ‘void kamping::measurements::Timer<CommunicatorType>::aggregate_and_print(Printer&&) [with Printer = kamping::measurements::SimpleJsonPrinter<double>; CommunicatorType = kamping::Communicator<>]’
/home/lukas/projects/kamping/examples/usage/timer_example.cpp:87:26: required from here
/home/lukas/projects/kamping/include/kamping/measurements/printer.hpp:83:51: warning: declaration of ‘_internal_printer’ shadows a member of ‘kamping::measurements::SimpleJsonPrinter<double>’ [-Wshadow]
83 | internal::ScalarOrVectorPrinter<Duration> _internal_printer{_outstream};
| ^~~~~~~~~~~~~~~~~
/home/lukas/projects/kamping/include/kamping/measurements/printer.hpp:131:9: note: shadowed declaration is here
131 | _internal_printer; ///< Internal printer able to print either a scalar or vector of durations.
| ^~~~~~~~~~~~~~~~~
Sadly, one of the spelling mistakes hid a warning message... @mschimek Is that your code?