Added difference operator to the sequence number

git-svn-id: https://svn.apache.org/repos/asf/incubator/qpid/trunk/qpid@557570 13f79535-47bb-0310-9956-ffa450edef68

2 files changed, 14 insertions, 0 deletions

diff --git a/cpp/src/qpid/framing/SequenceNumber.cpp b/cpp/src/qpid/framing/SequenceNumber.cpp
index 9bba67d4ae..ea1a34b1cf 100644
--- a/cpp/src/qpid/framing/SequenceNumber.cpp
+++ b/cpp/src/qpid/framing/SequenceNumber.cpp
@@ -60,3 +60,14 @@ bool SequenceNumber::operator>(const SequenceNumber& other) const
 {
     return other < *this;
 }
+
+namespace qpid {
+namespace framing {
+
+int32_t operator-(const SequenceNumber& a, const SequenceNumber& b)
+{
+    int32_t result = a.value - b.value;    
+    return result;
+}
+
+}}
diff --git a/cpp/src/qpid/framing/SequenceNumber.h b/cpp/src/qpid/framing/SequenceNumber.h
index 6d38084a25..bf9d133cef 100644
--- a/cpp/src/qpid/framing/SequenceNumber.h
+++ b/cpp/src/qpid/framing/SequenceNumber.h
@@ -32,6 +32,7 @@ namespace framing {
 class SequenceNumber
 {
     int32_t value;
+
  public:
     SequenceNumber();
     SequenceNumber(uint32_t v);
@@ -43,6 +44,8 @@ class SequenceNumber
     bool operator<(const SequenceNumber& other) const;
     bool operator>(const SequenceNumber& other) const;
     uint32_t getValue() const { return (uint32_t) value; }
+
+    friend int32_t operator-(const SequenceNumber& a, const SequenceNumber& b);
 };    
 
 }} // namespace qpid::framing