I don't think anything in the C parts of the C++ standard library throws its own exceptions. However, it's not completely unreasonable for a third party C libra

I don't think anything in the C parts of the C++ standard library throws its own exceptions. However, it's not completely unreasonable for a third party C library to use a C++ library underneath, and that might propagate any exceptions that the C++ side throws. This would be especially true if the C library were designed with some kind of plugin support, and someone supplied a C++ plugin.