The S&W MP40c (and other calibers) comes with or without a thumb safety.
I purchased the ‘with’ model. IMO carrying a pistol with a loaded chamber and no safety is asking for trouble.
Yes, Glocks have 3 ‘safeties’. But the long and short of it is, pull the trigger..Bang. No other manipulation is necessary.
I’ve owned and carried a glock for over 10 years. Granted I’m not a highly trained LEO but my firearm has never “accidentally” discharged.
I was thinking similar, but on the lines of a 1911. Thumb safety engaged, no bang, no matter how hard the trigger is pulled (e.g., by catching on part of a holster or clothing).