Despite the new liberal government indicating their desire to change the pot laws, it can still be a criminal offence if you are in possession of pot or marijuana or a similar narcotic.
If you are convicted for a pot possession charge then you will require a pardon or record suspension to get the criminal record removed. You will need to pay the fine and then wait the prescribed time to be eligible for the record removal.
If you are fingerprinted by the police and the pot charge was later dismissed, withdrawn, stayed or discharged, you still have an FPS number with the RCMP and a criminal check can show you have been fingerprinted by the police.
This is especially concerning if you are traveling to the US because they are not familiar with our justice system and they do not like drug charges of any kind no matter how small or insignificant. If the Americans see that you have been fingerprinted for a drug charge, they will deny you entry to the US. If that happens, then you will require a US Entry Waiver which is a complicated and expensive process.
Once your fingerprints, photos, court and police records are removed or destroyed, then you will be safe to travel without worry.
Here is an article in the NOW magazine entitled “Its Reefer Madness All Over Again” which highlights the issue of smoking pot illegally:
https://nowtoronto.com/news/features/it-s-reefer-madness-all-over-again/
Here is a recent article entitled “NDP Bill Calls for Decriminalization of Marijuana”:
http://www.timescolonist.com/news/local/ndp-bill-calls-for-decriminalization-of-marijuana-1.2276869