To clarify, I'm talking about using the laptop as a power source to charge other devices (phones, tablets, etc) off your laptop's USB ports.
If you plug them in while the laptop is asleep they won't start charging. If you plug them in while the laptop is awake they'll start to charge, and they'll keep going if the computer goes to sleep later.
If you laptop isn't charging itself while plugged in to the wall you have other problems.
If you plug them in while the laptop is asleep they won't start charging. If you plug them in while the laptop is awake they'll start to charge, and they'll keep going if the computer goes to sleep later.
If you laptop isn't charging itself while plugged in to the wall you have other problems.