I should explain that when I shoot serious work that I care about, and intend to eventually print, I gauge what the lighting conditions are with my meter, and then I shoot a whole roll in those conditions. It could be a portrait session, an early morning landscape outing, urban landscapes in very high contrast lighting, or night photography, etc... I never mix over- and under-exposure on the same roll. That would not work very well in my opinion.
There are times that I use the 35mm camera more for documentation, like a wedding, a party, vacation trip, or similar, where I have all kinds of mixed lighting on the same roll of film. Then it becomes a compromise, where I aim for a happy medium, and I usually end up scanning the resulting frames. It works fine for that purpose. Usually there is enough latitude in the film to make even pretty good prints, and once in a while excellent even if I happen to strike a happy coincidence with exposure...
But I always take great care in exposing my film so that I can fine tune the results for a particular lighting condition, in order to get that very last bit of performance out of the film in order to step up from a 'pretty good' print, to a (in my opinion) really fine print. In my darkroom, and in my prints it makes a big difference.