Xcode 16.3 build error: Implicit instantiation of undefined template 'std::char_traits<unsigned char>'

[denny-msft]

Xcode 16.3 removed the base template for std::char_traits and is causing build failures with Implicit instantiation of undefined template 'std::char_traits<unsigned char>'.

Here are the release notes with the deprecation: https://developer.apple.com/documentation/xcode-release-notes/xcode-16_3-release-notes#Deprecations

We are consuming this via OneDsCppSdk.iOS CocoaPod, and seems like the downstream dependencies will need to change usage of std::char_traits.

[lalitb]

@denny-msft - Would you be adding a PR to fix this issue?

[maglims]

We are facing the same issue. Is there a ETA on when this will be fixed?

[bmehta001]

Hi @denny-msft and @maglims, Thanks for raising this issue. It has been fixed by #1454, which bumped nlohmann/json to 3.12.0 which now defines its own internal char_traits. The fix is in the latest release v3.10.159.1. Please let me know if you have any questions.