In regards to the homeless individual being a drug addict, I'd say reluctantly.
Reluctant because I don't like being bamboozled for money (it doesn't matter if it's 50¢ or $1) on top of supporting somebody's drug habit. It makes me feel like I'm wasting my hard-earned money as well as my compassion and empathy.
Yeah, yeah, yeah I know some may say well whatever they do with the money after you gave them it is their business but, I'm not interested in helping you get high.
Now don't get me wrong, I'm sympathetic to the homeless individuals who need food, clothes, toiletries, shelter, etc, and want to be better but I have no feelings for somebody throwing their life away willing to be an addict, especially an addict that has no interest in improving their life. Now I know it's not easy for addicts to change but you've got to make the effort and show people that you want to change and in return, people will be more inclined to be supportive.