The implementation (Value & (Value - 1) == 0) returns true for powers of two (including 2^0 = 1), but also trivially returns true for 0, which is presumably unintended. Should be simple enough to fix.
Thats sounds more like compiler issue not UE4
I was stating that the implementation they have for the function returns true for 0 as well as powers of two. 0 & -1 == 0, regardless of compiler.
ah sorry you right is function, i’m stupid now i get it >.< if you know the fix why dont you submit the fix yourself on github? 
Hello,
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