feat(joystick/vector): Update to return const ref where possible

[finger563]

Description

• Update espp::Vector2d and espp::Joystick to return const references where possible

Motivation and Context

Reduces the amount of unnecessary copies in application code

How has this been tested?

Build and run math/example and joystick/example

Screenshots (if appropriate, e.g. schematic, board, console logs, lab pictures):

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• Documentation Update
• Hardware (schematic, board, system design) change
• Software change

Checklist:

• My change requires a change to the documentation.
• I have added / updated the documentation related to this change via either README or WIKI

Software

• I have added tests to cover my changes.
• I have updated the .github/workflows/build.yml file to add my new test to the automated cloud build github action.
• All new and existing tests passed.
• My code follows the code style of this project.

[Copilot]

Copilot reviewed 3 out of 3 changed files in this pull request and generated 1 comment.

Comments suppressed due to low confidence (4)

components/math/include/vector2d.hpp:79

• [nitpick] Returning a const reference for x() is effective for large types, but if T is a primitive or small type this change may not be optimal; consider adding documentation or a conditional specialization to clarify the design intent.

const T &x() const { return x_; }

components/joystick/src/joystick.cpp:77

• [nitpick] Ensure that returning a const reference for position() does not lead to unexpected lifetime issues for client code, particularly if the internal state may change.

const espp::Vector2f &espp::Joystick::position() const { return position_; }

components/joystick/src/joystick.cpp:79

• [nitpick] Verify that clients using raw() do not unintentionally rely on a copy of the data, as the returned reference is directly tied to the object’s internal state.

const espp::Vector2f &espp::Joystick::raw() const { return raw_; }

components/joystick/include/joystick.hpp:216

• [nitpick] Similarly, document the lifetime assumptions for the raw() getter to ensure that downstream clients understand that the returned reference is valid only as long as the underlying object remains unchanged.

const espp::Vector2f &raw() const;

[github-actions]

✅Static analysis result - no issues found! ✅