- added MultiBuffer

- improved tests

delay/tests/test_buffer_multi.cpp

@@ -0,0 +1,44 @@
+#include <delay/buffer_multi.hpp>
+#include <cstdio>
+
+#include <iostream>
+
+static void info()
+{
+	std::cout << "----------------------------------------------" << std::endl;
+	std::cout << "Start test_buffer_multi()" << std::endl;
+	std::cout << "----------------------------------------------" << std::endl;
+}
+
+int test_buffer_multi()
+{
+	info();
+	dsp::BufferMulti<int>buffer(5, 20);
+	printf("Buffer capacity = %zu\n", buffer.capacity());
+
+	for (int i=0; i < 10; i++)
+	{
+		for (int c=0; c < 5; c++)
+		{
+			buffer.at(c, 0) = i+1;
+		}
+		buffer += 1;
+
+	}
+
+	buffer.reset();
+	for (int i=0; i < 10; i++)
+	{
+		for (int c=0; c < 5; c++)
+		{
+			int v = buffer.at(c, i);
+			printf("c=%d: i=%d: v=%d\n", c, i, v);
+		}
+	}
+
+	for(const auto&i : buffer)
+	{
+	}
+
+	return 0;
+}