1 files changed, 13 insertions, 0 deletions
diff --git a/unsupported/Eigen/CXX11/src/Tensor/TensorForwardDeclarations.h b/unsupported/Eigen/CXX11/src/Tensor/TensorForwardDeclarations.h
index c22444e6f..fbeb9c59a 100644
--- a/unsupported/Eigen/CXX11/src/Tensor/TensorForwardDeclarations.h
+++ b/unsupported/Eigen/CXX11/src/Tensor/TensorForwardDeclarations.h
@@ -29,6 +29,7 @@ template<typename Axis, typename LeftXprType, typename RightXprType> class Tenso
 template<typename Dimensions, typename LeftXprType, typename RightXprType> class TensorContractionOp;
 template<typename TargetType, typename XprType> class TensorConversionOp;
 template<typename Dimensions, typename InputXprType, typename KernelXprType> class TensorConvolutionOp;
+template<typename FFT, typename XprType, int FFTDataType, int FFTDirection> class TensorFFTOp;
 template<typename PatchDim, typename XprType> class TensorPatchOp;
 template<DenseIndex Rows, DenseIndex Cols, typename XprType> class TensorImagePatchOp;
 template<DenseIndex Planes, DenseIndex Rows, DenseIndex Cols, typename XprType> class TensorVolumePatchOp;
@@ -58,6 +59,18 @@ struct DefaultDevice;
 struct ThreadPoolDevice;
 struct GpuDevice;
 
+enum FFTResultType {
+  RealPart = 0,
+  ImagPart = 1,
+  BothParts = 2
+};
+
+enum FFTDirection {
+    FFT_FORWARD = 0,
+    FFT_REVERSE = 1
+};
+
+
 namespace internal {
 
 template <typename Device, typename Expression>