Use smart_holder branch machinery to be able to pass a Bot instance by both unique_ptr and shared_ptr interchangeably.

PiperOrigin-RevId: 517914864
Change-Id: Ia4a10b798d81d622f681ef769082ca01d833238d

Author: DeepMind Technologies Ltd

open_spiel/python/pybind11/bots.cc

@@ -17,9 +17,7 @@
 #include <stdint.h>
 
 #include <memory>
-#include <new>
 #include <string>
-#include <utility>
 
 #include "open_spiel/algorithms/evaluate_bots.h"
 #include "open_spiel/algorithms/is_mcts.h"
@@ -99,8 +97,7 @@ class PyBot : public Bot {
         "inform_action",  // Name of function in Python
         InformAction,     // Name of function in C++
         state,            // Arguments
-        player_id,
-        action);
+        player_id, action);
   }
   void InformActions(const State& state,
                      const std::vector<Action>& actions) override {
@@ -153,7 +150,7 @@ class PyBot : public Bot {
 }  // namespace
 
 void init_pyspiel_bots(py::module& m) {
-  py::class_<Bot, PyBot> bot(m, "Bot");
+  py::classh<Bot, PyBot> bot(m, "Bot");
   bot.def(py::init<>())
       .def("step", &Bot::Step)
       .def("restart", &Bot::Restart)
@@ -227,7 +224,7 @@ void init_pyspiel_bots(py::module& m) {
       .def("to_string", &SearchNode::ToString)
       .def("children_str", &SearchNode::ChildrenStr);
 
-  py::class_<algorithms::MCTSBot, Bot>(m, "MCTSBot")
+  py::classh<algorithms::MCTSBot, Bot>(m, "MCTSBot")
       .def(
           py::init([](std::shared_ptr<const Game> game,
                       std::shared_ptr<Evaluator> evaluator, double uct_c,
@@ -253,7 +250,7 @@ void init_pyspiel_bots(py::module& m) {
              algorithms::ISMCTSFinalPolicyType::kMaxVisitCount)
       .value("MAX_VALUE", algorithms::ISMCTSFinalPolicyType::kMaxValue);
 
-  py::class_<algorithms::ISMCTSBot, Bot>(m, "ISMCTSBot")
+  py::classh<algorithms::ISMCTSBot, Bot>(m, "ISMCTSBot")
       .def(py::init<int, std::shared_ptr<Evaluator>, double, int, int,
                     algorithms::ISMCTSFinalPolicyType, bool, bool>(),
            py::arg("seed"), py::arg("evaluator"), py::arg("uct_c"),

open_spiel/python/pybind11/pybind11.h

@@ -34,7 +34,9 @@
 // in one place to help with consistency.
 
 namespace open_spiel {
+
 class NormalFormGame;
+class Bot;
 
 namespace matrix_game {
 class MatrixGame;
@@ -43,13 +45,22 @@ class MatrixGame;
 namespace tensor_game {
 class TensorGame;
 }
+
+namespace algorithms {
+class MCTSBot;
+class ISMCTSBot;
+}  // namespace algorithms
+
 }  // namespace open_spiel
 
 PYBIND11_SMART_HOLDER_TYPE_CASTERS(open_spiel::State);
 PYBIND11_SMART_HOLDER_TYPE_CASTERS(open_spiel::Game);
 PYBIND11_SMART_HOLDER_TYPE_CASTERS(open_spiel::NormalFormGame);
 PYBIND11_SMART_HOLDER_TYPE_CASTERS(open_spiel::matrix_game::MatrixGame);
 PYBIND11_SMART_HOLDER_TYPE_CASTERS(open_spiel::tensor_game::TensorGame);
+PYBIND11_SMART_HOLDER_TYPE_CASTERS(open_spiel::Bot);
+PYBIND11_SMART_HOLDER_TYPE_CASTERS(open_spiel::algorithms::MCTSBot);
+PYBIND11_SMART_HOLDER_TYPE_CASTERS(open_spiel::algorithms::ISMCTSBot);
 
 // Custom caster for GameParameter (essentially a variant).
 namespace pybind11 {