c10::optional -> std::optional

[r-barnes]

Since Nov 29, 2023, PyTorch's c10::optional has been an alias for std::optional (link).

As of Dec 17, 2024, PyTorch has begun taking steps to begin removing the c10::optional alias entirely (link). The old API remains available, for now, but you can check whether your code has eliminated all instances of deprecated APIs by compiling with C10_NODEPRECATED defined as a preprocessor flag (-DC10_NODEPRECATED).

This PR converts your existing usages of c10::optional to std::optional (same for nullopt).

(Additional deprecated APIs include C10_UNUSED, C10_NODISCARD, and c10::string_view.)

[codecov-commenter]

⚠️ Please install the to ensure uploads and comments are reliably processed by Codecov.

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 98.20%. Comparing base (140d3ad) to head (82f34d0).
Report is 10 commits behind head on master.

❗ Your organization needs to install the Codecov GitHub app to enable full functionality.

Additional details and impacted files

@@            Coverage Diff             @@
##           master     #473      +/-   ##
==========================================
+ Coverage   97.23%   98.20%   +0.97%     
==========================================
  Files          10       10              
  Lines         217      223       +6     
==========================================
+ Hits          211      219       +8     
+ Misses          6        4       -2     

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.

[guanshaoheng]

when compiling on Windows in github action, I was told

D:\a\PretextView\PretextView\subprojects\pytorch_scatter\csrc\cpu\segment_coo_cpu.h(5,32): error C2039: 'optional': is not a member of 'std' [D:\a\PretextView\PretextView\subprojects\pytorch_scatter\build\torchscatter.vcxproj]
(compiling source file '../csrc/cpu/segment_coo_cpu.cpp')
C:\Program Files\Microsoft Visual Studio\2022\Enterprise\VC\Tools\MSVC\14.42.34433\include\forward_list(23,1):

For details, please check here.

any idea how to solve this?

I am using the newest libtorch for Windows.

Thanks for your help.

Best
Shaoheng