mbv: move a few things around

mbv/lib/buffer.h

@@ -0,0 +1,30 @@
+#pragma once
+
+#include <span>
+#include <utility>
+
+struct buffer {
+    std::span<std::byte> data;
+
+    buffer() = default;
+    buffer(std::span<std::byte> d) : data(d) {}
+
+    static buffer make(size_t size) {
+        return buffer({new std::byte[size], size});
+    }
+
+    buffer(buffer& other) = delete;
+    buffer& operator=(buffer& other) = delete;
+
+    buffer(buffer&& other) : data(std::exchange(other.data, {})) {}
+    buffer& operator=(buffer&& other) {
+        data = std::exchange(other.data, {});
+        return *this;
+    }
+
+    ~buffer() {
+        if (data.data()) {
+            delete[] data.data();
+        };
+    }
+};