2 files changed, 48 insertions, 0 deletions
diff --git a/number.cpp b/number.cpp
index e942cf2..f6f445c 100644
--- a/number.cpp
+++ b/number.cpp
@@ -1,5 +1,46 @@
 #include "number.h"
 
+/* Operations {{{ */
+
+number
+number::operator+(const number &n) const
+{
+    /* We make sure our object is greater than or equal to n. */
+    if (*this < n) {
+        return n.operator+(*this);
+    }
+
+    number result;
+
+    auto it = _operands.cbegin();
+    auto it_n = n._operands.cbegin();
+
+    bool carry = false;
+
+    while (it != _operands.cend()) {
+        const auto n1 = *it;
+        const auto n2 = *it_n;
+
+        result._operands.push_back(n1 + n2 + (carry ? 1 : 0));
+
+        if (carry && (n1 == UINT64_MAX)) {
+            carry = true;
+        } else {
+            carry = ((UINT64_MAX - n1 - (carry ? 1 : 0)) < n2);
+        }
+
+        ++it;
+        ++it_n;
+    }
+
+    if (carry) {
+        result._operands.push_back(1);
+    }
+
+    return result;
+}
+
+/* }}} */
 /* Comparison operators {{{ */
 
 bool
diff --git a/number.h b/number.h
index c508a81..ca5075e 100644
--- a/number.h
+++ b/number.h
@@ -9,6 +9,13 @@ public:
     number() = default;
 
     /**
+     * \brief Return the result of the addition of a number and this number.
+     *
+     * \param n The number to add to this number.
+     */
+    number operator+(const number &n) const;
+
+    /**
      * \brief Tells whether the number passed as parameter is strictly less
      * than this number.
      *