I found a disabled test in Boost.Iostreams called stream_state_test. It was disabled because it was thought it only tests the standard library implementation. Partially true, but it also tests some parts of iostreams so I have been working to re-enable it along with the generic CI upgrades. It looks like libstdc++ and the standard library that comes with MSVC (is it still Dinkumware? It used to be...) handle exceptions on stream seekg and seekp differently. I haven't consulted the standards documents yet, but I found this reference for exception handling: http://www.cplusplus.com/reference/istream/istream/seekg/ which states, " Any exception thrown by an internal operation is caught and handled by the function, setting badbit <http://www.cplusplus.com/ios_base::badbit>. " Sitting in the debugger where the test throws an exception in error_device::seek, there is no exception handling within iostreams or in msvcp140d code paths for a call to seekg, while the libstdc++ implementation is able to pass all of the tests. This leads to a couple questions: 1. Are the standards clear in this area? 2. Is someone violating them? A cursory review (such as this) leads me to believe that the MSVC C++ runtime implementation is not properly handling exceptions here. The sources for seekg in libstdc++ wrap the internals in a try catch in order to restore state. The sources for seekg in the MSVCPRT do not. - Jim