diff --git a/game_state.h b/game_state.h
index a306624..586a1e0 100644
--- a/game_state.h
+++ b/game_state.h
@@ -47,20 +47,9 @@ struct Card {
   rank_t rank;
   uint8_t copy;
 
-  Card& operator++() {
-    rank++;
-    return *this;
-  }
-
-  Card successor() {
-    return {suit, static_cast<rank_t>(rank + 1)};
-  }
-
-  const Card operator++(int) {
-    Card ret = *this;
-    rank++;
-    return ret;
-  }
+  Card& operator++();
+  Card successor() const;
+  const Card operator++(int);
 
   auto operator<=>(const Card&) const = default;
 };
@@ -93,28 +82,7 @@ template<std::size_t num_suits>
 using Stacks = std::array<rank_t, num_suits>;
 
 template<std::size_t num_suits>
-std::ostream& operator<<(std::ostream& os, const Stacks<num_suits>& stacks) {
-  for (size_t i = 0; i < stacks.size() - 1; i++) {
-    os << +stacks[i] << ", ";
-  }
-  os << +stacks.back();
-  return os;
-}
-
-template <std::size_t num_suits>
-struct CardSetSpecification {
-  using AdditionalCardsFlags = std::bitset<num_suits * (starting_card_rank - 1)>;
-
-  Stacks<num_suits> stacks {};
-  AdditionalCardsFlags additional_cards_flags {};
-};
-
-
-template <std::size_t num_suits, std::size_t num_players, std::size_t hand_size>
-struct PartialHanabiInstance {
-  std::array<boost::container::static_vector<Card, hand_size>, num_players> initial_cards;
-  CardSetSpecification<num_suits> initial_state;
-};
+std::ostream& operator<<(std::ostream& os, const Stacks<num_suits>& stacks);
 
 struct CardMultiplicity {
   Card card;
@@ -126,13 +94,9 @@ struct CardMultiplicity {
 template<std::size_t num_suits>
 struct CardPositions {
 
-  const player_t & operator[](const Card& card) const {
-      return _card_positions[card.suit][card.rank][card.copy];
-  };
+  const player_t & operator[](const Card& card) const;
 
-  player_t & operator[](const Card& card) {
-    return _card_positions[card.suit][card.rank][card.copy];
-  };
+  player_t & operator[](const Card& card);
 
   auto operator<=>(const CardPositions&) const = default;
 
@@ -189,7 +153,7 @@ public:
 };
 
 template <std::size_t num_suits, std::size_t num_players, std::size_t hand_size, std::uint8_t max_draw_pile_size>
-std::ostream& operator<<(std::ostream& os, const HanabiState<num_suits, num_players, hand_size, max_draw_pile_size> hanabi_state);
+std::ostream& operator<<(std::ostream& os, HanabiState<num_suits, num_players, hand_size, max_draw_pile_size> hanabi_state);
 
 #include "game_state.hpp"
 
diff --git a/game_state.hpp b/game_state.hpp
index e7b2196..36b3180 100644
--- a/game_state.hpp
+++ b/game_state.hpp
@@ -3,6 +3,40 @@
 #include <iterator>
 
 
+Card& Card::operator++() {
+  rank++;
+  return *this;
+}
+
+Card Card::successor() const {
+  return {suit, static_cast<rank_t>(rank + 1)};
+}
+
+const Card Card::operator++(int) {
+  Card ret = *this;
+  rank++;
+  return ret;
+}
+
+template<std::size_t num_suits>
+std::ostream& operator<<(std::ostream& os, const Stacks<num_suits>& stacks) {
+  for (size_t i = 0; i < stacks.size() - 1; i++) {
+    os << +stacks[i] << ", ";
+  }
+  os << +stacks.back();
+  return os;
+}
+
+template<std::size_t num_suits>
+const player_t & CardPositions<num_suits>::operator[](const Card& card) const {
+    return _card_positions[card.suit][card.rank][card.copy];
+};
+
+template<std::size_t num_suits>
+player_t & CardPositions<num_suits>::operator[](const Card& card) {
+  return _card_positions[card.suit][card.rank][card.copy];
+};
+
 template <size_t num_suits, size_t num_players, size_t hand_size, uint8_t max_draw_pile_size>
 Action HanabiState<num_suits, num_players, hand_size, max_draw_pile_size>::clue() {
   assert(_num_clues > 0);