I had exactly this last week in Vancouver, very swift given how long the queue was (British citizen if that helps).

"Why are you visiting Canada?"

"I"m here for a conference"

"What's the conference about?"

"Computer vision, you know, programming research"

"How long are you staying?"

"A week"

Stamp

There was a point on the outbound journey where they were checking everyone's passports by the scanner (i.e. you'd go through and everyone would set the alarm off, but it seemed to be a passport check rather than anything else), as soon as they saw it was British they lost interest.