fix(cpp): UE 5.8 compatibility for FJsonObject::Values key type - #55
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UE 5.8 changed FJsonObject::Values key from FString to UE::FSharedString. Iterating ->Values and using Pair.Key as an FString broke compilation (C2440/C2664). operator* yields const TCHAR* on both FString (5.7) and UE::FSharedString (5.8), so dereference the key at the two break sites: - MCPythonTcpServer.cpp: FString KeyString = *Pair.Key; - MCPythonHelper.cpp: FindPinByName(NewNode, FString(*Pair.Key), ...) A third site (MCPythonHelper_BehaviorTree.cpp) already used *Pair.Key. Verified: BuildPlugin succeeds on UE 5.8; change is source-compatible with 5.7 (standard FString API).
This was referenced Jun 19, 2026
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What
UE 5.8 changed
FJsonObject::Values' key type fromFStringtoUE::FSharedString. Iterating->Valuesand usingPair.Keydirectly as anFStringbroke compilation on 5.8 (C2440/C2664). This ports the source so it builds on both 5.7 and 5.8.Fix
operator*yieldsconst TCHAR*on bothFString(5.7) andUE::FSharedString(5.8), so dereference the key at the two break sites:MCPythonTcpServer.cpp—FString KeyString = *Pair.Key;MCPythonHelper.cpp—FindPinByName(NewNode, FString(*Pair.Key), …)A third iteration site (
MCPythonHelper_BehaviorTree.cpp) already used*Pair.Key, so no change there.Verification
RunUAT BuildPlugin→ BUILD SUCCESSFUL (DLL + PDB +.modulesproduced).*→const TCHAR*), so the already-releasedUnrealMCPython_5.7_2.2.0.zipstays valid. (5.7 not re-built here — engine no longer installed on the build machine; change is provably backward-compatible.)Not covered
In-editor (gate 3) / E2E (gate 4) have not been run on a 5.8 editor — only compile+link verified. Recommend dropping the 5.8 binary into a 5.8 editor and running
run_all+ E2E before relying on it in production.Release
No version bump:
2.2.0now ships two engine-target binaries (_5.7_/_5.8_), same as the KawaiiPhysics per-version model. The 5.8 zip is built and ready to attach to the existingv2.2.0release.