I have a Ruger 1911. The grip safety is an integral part of the 1911 design; I doubt if any 1911s do not have this feature.
My 1911 (and I assume all of the others) also has a safety on the side that can be disengaged with the thumb.
So, for a 1911, the safety would have to be disengaged and the grip held sufficiently tight (which is no more than a comfortable shooting grip) to disengage the grip safety before you could fire.
To carry a Glock with a round in the chamber is like carrying a Model 1911 cocked, unlocked, with a round in the chamber and the grip safety taped down.
No one would carry a Model 1911 in this condition, but people carry a Glock in this condition and think nothing of it.