On the subject of flowcharts, I'll offer a different take. Flowcharts are just another form of documentation, and by no means are they necessarily the first step. For complicated projects, as an intermediate step, I'll sometimes draw a flowchart to help me clarify (to myself or others) how a particular subsystem works/should work, but typically the flowchart, if any, is created at the end, once the software has been written.
Personally, I've never found it helpful to start with a flowchart. I know a lot of developers swear by them, but we humans are a varied lot and there is no one-size-fits-all approach to software development. I prefer to start with an English-language description of the problem, the desired outcomes, and the constraints. Depending on the project, this can be an informal "thinking out loud", or a full software requirements specification (SRS). Then, I iterate (in English) on how it can be solved. Very high-level flowcharts can be useful here, as can writing a basic user manual or API specification. Solution ideas are transformed into implementation ideas, converging to a development plan. Again, this can be an informal set of notes, or a full-on software design document (SDD). Once the relevant stakeholders agree that the SDD satisfies the SRS, coding begins.
In any case, the OP seems to be asking how to use C++ classes. Are flowcharts really the best path for this goal?
Personally, I've never found it helpful to start with a flowchart. I know a lot of developers swear by them, but we humans are a varied lot and there is no one-size-fits-all approach to software development. I prefer to start with an English-language description of the problem, the desired outcomes, and the constraints. Depending on the project, this can be an informal "thinking out loud", or a full software requirements specification (SRS). Then, I iterate (in English) on how it can be solved. Very high-level flowcharts can be useful here, as can writing a basic user manual or API specification. Solution ideas are transformed into implementation ideas, converging to a development plan. Again, this can be an informal set of notes, or a full-on software design document (SDD). Once the relevant stakeholders agree that the SDD satisfies the SRS, coding begins.
In any case, the OP seems to be asking how to use C++ classes. Are flowcharts really the best path for this goal?