Zero cost refers to runtime cost, as in the compiled code. > You still pay, often in something that you didn't bother to measure, which (in C++) is usually com

Zero cost refers to runtime cost, as in the compiled code. > You still pay, often in something that you didn't bother to measure, which (in C++) is usually compile time or programmer productivity or programmer cognitive cost or compiler complexity. Obviously everything is about tradeoffs. If an abstraction is making everything worse for you, then don’t use it. I don’t think it’s fair to try to list every possible downside of an abstraction, as there are obviously also downsides to not using abstractions otherwise we wouldn’t have these options. Zero cost refers to the compiled code and runtime performance.