Take advantage of unique_ptr and move construction for Buffer

Since Buffer has always implemented its copy constructor with a deep
copy, its Members object will never have multiple owners. Change to unique_ptr.

Also implement move constructors for Buffer, since there may be cases
where a deep copy is not needed.

1 files changed, 13 insertions, 1 deletions

diff --git a/libqpdf/Buffer.cc b/libqpdf/Buffer.cc
index 4e8a17ae..98a524ce 100644
--- a/libqpdf/Buffer.cc
+++ b/libqpdf/Buffer.cc
@@ -48,12 +48,24 @@ Buffer::operator=(Buffer const& rhs)
     return *this;
 }
 
+Buffer::Buffer(Buffer&& rhs) noexcept :
+    m(std::move(rhs.m))
+{
+}
+
+Buffer&
+Buffer::operator=(Buffer&& rhs) noexcept
+{
+    std::swap(this->m, rhs.m);
+    return *this;
+}
+
 void
 Buffer::copy(Buffer const& rhs)
 {
     if (this != &rhs) {
         this->m =
-            std::shared_ptr<Members>(new Members(rhs.m->size, nullptr, true));
+            std::unique_ptr<Members>(new Members(rhs.m->size, nullptr, true));
         if (this->m->size) {
             memcpy(this->m->buf, rhs.m->buf, this->m->size);
         }