I would never hit a man or a woman as the aggressor. Should they try to hit me, however, I will use reasonable force to repel their physical attack (reasonable force meaning I would use a level of force enough to repel their attack and no more than what they are attacking me with) and ensure the safety of myself, my family, or my friends.
So if it was a woman (to stay on topic) if she was trying to slap me, I would do something to prevent getting slapped, maybe grab her wrists. Her slapping me doesn't justify me belting her in the face. But if she's got a knife, she's raising the stakes... I will meet those stakes accordingly to ensure my health and well-being.
If its a man, and he slaps me (maybe he's a sissy) I am going to do whatever it takes to prevent getting slapped, I wouldn't up and belt a guy in the face for that. If he pulls a knife, my level of force will escalate accordingly... same as a woman.
Regardless of sex, I would meet any attack with reasonable force, as set by the aggressor. They make the bed, they're gunna sleep in it, man or woman. Hell if a DOG attacks me to maim me, if I get my hands on some stick or something its getting a whack over the head...