add a capture operator.

src/include/migraphx/op/capture.hpp

+#ifndef MIGRAPHX_GUARD_OPERATORS_CAPTURE_HPP
+#define MIGRAPHX_GUARD_OPERATORS_CATTURE_HPP
+
+#include <array>
+#include <migraphx/operation.hpp>
+#include <migraphx/check_shapes.hpp>
+#include <migraphx/stringutils.hpp>
+#include <migraphx/streamutils.hpp>
+#include <migraphx/literal.hpp>
+#include <migraphx/shape_for_each.hpp>
+#include <migraphx/config.hpp>
+#include <cmath>
+#include <utility>
+
+namespace migraphx {
+inline namespace MIGRAPHX_INLINE_NS {
+namespace op {
+
+struct capture
+{
+    std::function<void(std::vector<argument>) f;
+    template<class Self, class F>
+    static auto reflect(Self& self, F f)
+    {
+        return pack(f(self.f, "func"));
+    }
+
+    std::string name() const { return "capputure"; }
+
+    shape compute_shape(std::vector<shape> inputs) const
+    {
+        return inputs.front();
+    }
+
+    argument compute(const shape& output_shape, std::vector<argument> args) const
+    {
+        argument result{output_shape};
+        args.push_back(result);
+        f(args);
+
+        return result;
+    }
+};
+
+} // namespace op
+} // namespace MIGRAPHX_INLINE_NS
+} // namespace migraphx
+
+#endif

src/include/migraphx/operators.hpp

@@ -11,6 +11,7 @@
 #include <migraphx/op/batch_norm.hpp>
 #include <migraphx/op/binary.hpp>
 #include <migraphx/op/broadcast.hpp>
+#include <migraphx/op/capture.hpp>
 #include <migraphx/op/common.hpp>
 #include <migraphx/op/concat.hpp>
 #include <migraphx/op/contiguous.hpp>