Use std::optional for possibly None argument.

1 files changed, 4 insertions, 5 deletions

diff --git a/src/python/gudhi/bottleneck.cc b/src/python/gudhi/bottleneck.cc
index 3a0fe473..1cf3283c 100644
--- a/src/python/gudhi/bottleneck.cc
+++ b/src/python/gudhi/bottleneck.cc
@@ -9,18 +9,17 @@
  */
 
 #include <gudhi/Bottleneck.h>
-
+#include <optional>
 #include <pybind11_diagram_utils.h>
+#include <pybind11/stl.h>
 
 // Indices are added internally in bottleneck_distance, they are not needed in the input.
 static auto make_point(double x, double y, py::ssize_t) { return std::pair(x, y); };
 
 // For compatibility with older versions, we want to support e=None.
-// In C++17, the recommended way is std::optional<double>.
-double bottleneck(Dgm d1, Dgm d2, py::object epsilon)
+double bottleneck(Dgm d1, Dgm d2, std::optional<double> epsilon)
 {
-  double e = (std::numeric_limits<double>::min)();
-  if (!epsilon.is_none()) e = epsilon.cast<double>();
+  double e = epsilon.value_or((std::numeric_limits<double>::min)());
   // I *think* the call to request() has to be before releasing the GIL.
   auto diag1 = numpy_to_range_of_pairs(d1, make_point);
   auto diag2 = numpy_to_range_of_pairs(d2, make_point);