EstimateCamPosePNP defined but not used Warnings

[Liam-Stow]

Describe the bug
In photonlib c++ on Windows, when #including photon/simulation/VisionSystemSim.h and building for the rio, warnings that static std::optional<PnpResult> EstimateCamPosePNP() is unused get printed to the build console.

To Reproduce
Steps to reproduce the behavior:

1. Create a blank cpp project (I used the Timed Robot Skeleton template)
2. Install photonlib v2025.0.0-beta-8
3. Add #include <photon/simulation/VisionSystemSim.h> or photon/estimation/VisionEstimation.h to Robot.h
4. Run WPILib: Build Robot Code from the vscode command pallet
5. View warnings in the console:

Warnings in file Robot.cpp ....
In file included from C:\Users\user\.gradle\caches\8.10.2\transforms\b21211e3f0e2860a6b96abf082501de9\transformed\photonlib-cpp-v2025.0.0-beta-8-headers/photon/simulation/PhotonCameraSim.h:31,
                 from C:\Users\user\.gradle\caches\8.10.2\transforms\b21211e3f0e2860a6b96abf082501de9\transformed\photonlib-cpp-v2025.0.0-beta-8-headers/photon/simulation/VisionSystemSim.h:38,
                 from C:\src\icrobotics\cpp-photon-test\src\main\include/Robot.h:6,
                 from C:\src\icrobotics\cpp-photon-test\src\main\cpp\Robot.cpp:1:
C:\Users\user\.gradle\caches\8.10.2\transforms\ba6d2d39cca1288f8b471feb14a98f32\transformed\photontargeting-cpp-v2025.0.0-beta-8-headers/photon/estimation/VisionEstimation.h:51:33: warning: 'std::optional<photon::PnpResult> photon::VisionEstimation::EstimateCamPosePNP(const Eigen::Matrix<double, 3, 3>&, const Eigen::Matrix<double, 8, 1>&, const std::vector<photon::PhotonTrackedTarget>&, const frc::AprilTagFieldLayout&, const photon::TargetModel&)' defined but not used [-Wunused-function]
   51 | static std::optional<PnpResult> EstimateCamPosePNP(
      |                                 ^~~~~~~~~~~~~~~~~~

Full warning messages: https://github.com/Liam-Stow/cpp-photon-test/blob/simplest-warning-producer/warnings.txt

Example project with this problem: https://github.com/Liam-Stow/cpp-photon-test/blob/simplest-warning-producer/src/main/include/Robot.h

Platform:

• Hardware Platform: Windows x64 (photonlib only, this doesn't relate to the coprocessor)
• Network Configuration (Connection between the Radio and any devices in between, such as a Network Switch): N/A
• PhotonVision Version: v2025.0.0-beta-8
• Browser (with Version) (Chrome, Edge, Firefox, etc.): N/A
• Camera(s) Used: N/A

WPILib project information:

• Project Version: 2025.1.1
• VS Code Version: 1.96.2
• WPILib Extension Version: 2025.1.1
• C++ Extension Version: 1.23.2
• Java Extension Version: 1.38.0
• Java Debug Extension Version: 0.58.1
• Java Dependencies Extension Version 0.24.1
• Java Version: 17
• Java Location: C:\Users\Public\wpilib\2025\jdk
• Vendor Libraries:
  • photonlib (v2025.0.0-beta-8)

Additional context

• Removing targetPlatform wpi.platforms.roborio from build.gradle removes this problem.
• Seems to only be a problem on Windows, we had a Linux machine build without the warnings.
• This problem persists when you actually use the VisionSystemSim.

[mcm001]

Could you please slap a [[maybe_unused]] on that function?