Unreal 32-bit build different #pragma pack from default


I am building the 32-bit target and have finally figured out that the Unreal build system is using a different packing alignment for the 32-bit build than the default. The packing alignment building from Unreal is 4 bytes where as the default alignment from build my libraries using 32-bit Visual Studio is the default of 8 bytes (‘not specified’ means 8 bytes).

Is this an optimization I am unaware of ? Is there some place I can change the compiler settings that Unreal is using ?

It would be a bit of pain to have completely different Win32 Release projects for my libraries just for Unreal.



I have solved it for now by using “#pragma pack” around the includes for the external libraries.

But it would be nice to know the above information :slight_smile: