whether freestanding implementations replace the statement of a trivial infinite loop with a call to the function std::this_thread::yield, [stmt.iter.general]
whether functions from Annex K of the C standard library are declared when C++ headers are included, [headers]
whether the implementation is hosted or freestanding, [compliance]
whether the sources for module units and header units on which the current translation unit has an interface dependency are required to be available during translation, [lex.phases]
whether the thread that executes main and the threads created by std::thread or std::jthread provide concurrent forward progress guarantees, [intro.progress]
whether values are rounded or truncated to the required precision when converting between time_t values and time_point objects, [time.clock.system.members]
which functions in the C++ standard library may be recursively reentered, [reentrancy]
which non-standard-layout objects containing no data are considered empty, [intro.object]
which scalar types have unique object representations, [meta.unary.prop]