corr: add forgotten file

Sample/Slice/SliceStack.h

+//  ************************************************************************************************
+//
+//  BornAgain: simulate and fit reflection and scattering
+//
+//! @file      Sample/Slice/SliceStack.h
+//! @brief     Defines class SliceStack.
+//!
+//! @homepage  http://www.bornagainproject.org
+//! @license   GNU General Public License v3 or higher (see COPYING)
+//! @copyright Forschungszentrum Jülich GmbH 2018
+//! @authors   Scientific Computing Group at MLZ (see CITATION, AUTHORS)
+//
+//  ************************************************************************************************
+
+#ifdef SWIG
+#error no need to expose this header to Swig
+#endif
+
+#ifndef USER_API
+#ifndef BORNAGAIN_SAMPLE_SLICE_SLICESTACK_H
+#define BORNAGAIN_SAMPLE_SLICE_SLICESTACK_H
+
+#include <vector>
+
+class Slice;
+
+//! A stack of Slice%s.
+//!
+//! @ingroup algorithms_internal
+
+class SliceStack : public std::vector<Slice> {
+public:
+    bool containsMagneticMaterial() const;
+};
+
+#endif // BORNAGAIN_SAMPLE_SLICE_SLICESTACK_H
+#endif // USER_API