1 files changed, 25 insertions, 5 deletions
diff --git a/include/book_store/book_count.hh b/include/book_store/book_count.hh
index a9c68c1..29e599b 100644
--- a/include/book_store/book_count.hh
+++ b/include/book_store/book_count.hh
@@ -2,7 +2,6 @@
 #define BOOK_COUNT_HH
 
 #include <ostream>
-#include <string>
 
 namespace book_store::product {
 class book_count {
@@ -16,8 +15,10 @@ public:
   book_count() = default;
   book_count(book_count_type count) : _count(count) {}
 
-  friend auto operator<<(std::ostream &output_stream, const book_count &price)
-      -> std::ostream & {
+  [[nodiscard]] auto value() const noexcept -> book_count_type;
+
+  friend auto operator<<(std::ostream &output_stream,
+                         const book_count &price) -> std::ostream & {
     output_stream << price._count;
 
     return output_stream;
@@ -27,10 +28,29 @@ public:
     return lhs._count == rhs._count;
   }
 
-  friend auto operator+(const book_count &lhs, const book_count &rhs)
-      -> book_count {
+  friend auto operator+(const book_count &lhs,
+                        const book_count &rhs) -> book_count {
     return {lhs._count + rhs._count};
   }
+
+  friend auto operator<(const book_count &lhs, const book_count &rhs) -> bool {
+    return lhs._count < rhs._count;
+  }
+
+  friend auto operator-(const book_count &lhs,
+                        const book_count &rhs) -> book_count {
+    return {lhs._count - rhs._count};
+  }
+
+  friend auto operator%(const book_count &lhs,
+                        const book_count &rhs) -> book_count {
+    return {lhs._count % rhs._count};
+  }
+
+  friend auto operator*(const book_count &lhs,
+                        const book_count &rhs) -> book_count {
+    return {lhs._count * rhs._count};
+  }
 };
 } // namespace book_store::product