Default Actions

Something not mentioned at all until now (and properly described in the next section, Default actions) is that Outcome can be programmed take various actions when the user tries to observe .value() when there is no value, and so on for the other possible state observations. Seeing as we are replacing the throwing overload of copy_file() in the Filesystem TS with a result returning edition instead, it would make sense if an attempt to observe the value of an unsuccessful fs_result threw the exact same filesystem_error as the Filesystem TS does. »