You could always have methods (for as long as I can remember at least, I started using .NET in 3.0 days), you just can't inherit structs or use virtual methods

You could always have methods (for as long as I can remember at least, I started using .NET in 3.0 days), you just can't inherit structs or use virtual methods because structs don't have virtual method table. You can implement interfaces however and override operators - it's very nice for implementing 3D graphics math primitives like vectors and matrices, way better than Java in this regard which was what got me into C# way back then.