This depends on what you are building. Don't commit the sin of early optimization.
Does a client of the framework you are writing -- which is probably using STL internally -- need a single instruction operation for adding a value for a call that you make less than 0.001% of the time?
Optimization is about end results. Apply the Pareto Principle, and don't forget that your users also need to compile your code in a reasonable amount of time.
Does a client of the framework you are writing -- which is probably using STL internally -- need a single instruction operation for adding a value for a call that you make less than 0.001% of the time?
Optimization is about end results. Apply the Pareto Principle, and don't forget that your users also need to compile your code in a reasonable amount of time.