Added unit tests for the circular_buffer and fixed a few things.

dlib/sliding_buffer/circular_buffer.h

@@ -59,8 +59,20 @@ namespace dlib
             return data[(i+offset)%data.size()]; 
         }
 
-        void resize(unsigned long size, const T& value = T()) { data.resize(size,value); }
-        void assign(unsigned long size, const T& value) { data.assign(size,value); }
+        void resize(unsigned long size) 
+        {  
+            offset = 0;
+            data.resize(size); 
+        }
+
+        void assign(
+            unsigned long size, 
+            const T& value
+        ) 
+        { 
+            offset = 0;
+            data.assign(size,value); 
+        }
 
         unsigned long size() const { return data.size(); }
 
@@ -126,6 +138,13 @@ namespace dlib
             return (*this)[size()-1];
         }
 
+        void swap( circular_buffer& item)
+        {
+            std::swap(item.offset, offset);
+            data.swap(item.data);
+        }
+
+
     private:
         std::vector<T> data;
 

dlib/sliding_buffer/circular_buffer_abstract.h

@@ -78,15 +78,22 @@ namespace dlib
         !*/
 
         void resize(
+            unsigned long new_size
+        ); 
+        /*!
+            ensures
+                - #size() == new_size
+        !*/
+
+        void assign(
             unsigned long new_size, 
-            const T& c = T()
+            const T& value
         ); 
         /*!
             ensures
                 - #size() == new_size 
-                - any element with index between 0 and new_size - 1 which was in the 
-                  circular_buffer before the call to resize() retains its value and index.
-                  All other elements have a value given by c.
+                - for all valid i:
+                    - (*this)[i] == value
         !*/
 
         unsigned long size(

dlib/test/sliding_buffer.cpp

@@ -304,6 +304,113 @@ namespace
 
 
 
+    void test_circular_buffer()
+    {
+        circular_buffer<int> buf;
+
+        DLIB_TEST(buf.size() == 0);
+
+        buf.assign(4, 0);
+        DLIB_TEST(buf.size() == 4);
+
+        DLIB_TEST(buf[0] == 0);
+        DLIB_TEST(buf[1] == 0);
+        DLIB_TEST(buf[2] == 0);
+        DLIB_TEST(buf[3] == 0);
+        buf.push_back(1);
+        DLIB_TEST(buf[0] == 0);
+        DLIB_TEST(buf[1] == 0);
+        DLIB_TEST(buf[2] == 0);
+        DLIB_TEST(buf[3] == 1);
+        buf.push_back(2);
+        DLIB_TEST(buf[0] == 0);
+        DLIB_TEST(buf[1] == 0);
+        DLIB_TEST(buf[2] == 1);
+        DLIB_TEST(buf[3] == 2);
+        buf.push_front(3);
+        DLIB_TEST(buf[0] == 3);
+        DLIB_TEST(buf[1] == 0);
+        DLIB_TEST(buf[2] == 0);
+        DLIB_TEST(buf[3] == 1);
+        buf.push_front(4);
+        DLIB_TEST(buf.front() == 4);
+        DLIB_TEST(buf[0] == 4);
+        DLIB_TEST(buf[1] == 3);
+        DLIB_TEST(buf[2] == 0);
+        DLIB_TEST(buf[3] == 0);
+
+        buf.assign(4, 5);
+        DLIB_TEST(buf[0] == 5);
+        DLIB_TEST(buf[1] == 5);
+        DLIB_TEST(buf[2] == 5);
+        DLIB_TEST(buf[3] == 5);
+
+        buf.push_back(3);
+        DLIB_TEST(buf[0] == 5);
+        DLIB_TEST(buf[1] == 5);
+        DLIB_TEST(buf[2] == 5);
+        DLIB_TEST(buf[3] == 3);
+        buf.push_back(2);
+        DLIB_TEST(buf[0] == 5);
+        DLIB_TEST(buf[1] == 5);
+        DLIB_TEST(buf[2] == 3);
+        DLIB_TEST(buf[3] == 2);
+        buf.push_back(1);
+        DLIB_TEST(buf[0] == 5);
+        DLIB_TEST(buf[1] == 3);
+        DLIB_TEST(buf[2] == 2);
+        DLIB_TEST(buf[3] == 1);
+        buf.push_back(0);
+        DLIB_TEST(buf[0] == 3);
+        DLIB_TEST(buf[1] == 2);
+        DLIB_TEST(buf[2] == 1);
+        DLIB_TEST(buf[3] == 0);
+        buf.push_back(-1);
+        DLIB_TEST(buf.back() == -1);
+        DLIB_TEST(buf[0] == 2);
+        DLIB_TEST(buf[1] == 1);
+        DLIB_TEST(buf[2] == 0);
+        DLIB_TEST(buf[3] == -1);
+
+        buf.resize(1);
+        buf[0] = 9;
+        DLIB_TEST(buf.size() == 1);
+        DLIB_TEST(buf[0] == 9);
+        buf.push_back(1);
+        DLIB_TEST(buf[0] == 1);
+        buf.push_back(4);
+        DLIB_TEST(buf[0] == 4);
+        buf.push_front(3);
+        DLIB_TEST(buf[0] == 3);
+
+        buf.clear();
+        DLIB_TEST(buf.size() == 0);
+
+        buf.assign(3, 0);
+
+        circular_buffer<int> buf2, buf3;
+
+        buf.push_back(1);
+        buf.push_back(2);
+
+        ostringstream sout;
+        serialize(buf, sout);
+        istringstream sin(sout.str());
+        deserialize(buf2, sin);
+
+        DLIB_TEST(buf.size() == buf2.size());
+        for (unsigned long i = 0; i < buf.size(); ++i)
+            DLIB_TEST(buf[i] == buf2[i]);
+
+        buf.swap(buf3);
+        DLIB_TEST(buf.size() == 0);
+        DLIB_TEST(buf3.size() == buf2.size());
+        for (unsigned long i = 0; i < buf3.size(); ++i)
+            DLIB_TEST(buf3[i] == buf2[i]);
+
+
+
+    }
 
 
 
@@ -323,6 +430,8 @@ namespace
             sliding_buffer_kernel_test<sliding_buffer<unsigned char>::kernel_1a>  ();
             dlog << LINFO << "testing kernel_1a_c";
             sliding_buffer_kernel_test<sliding_buffer<unsigned char>::kernel_1a_c>();
+
+            test_circular_buffer();
         }
     } a;