lib/ynl: make ynl_socket a move-only type

Copying ynl_socket will result in ynl_sock_destroy() being called
twice on the same ynl_sock *. Like other c++ "RAII" types that manage
a resource, copying should either be deep or disallowed, and moving
should be supported. This commit opts for disallowing copy
construction and assignment.

Signed-off-by: Daniel Zahka <[email protected]>

Author: Daniel Zahka

lib/ynl-cpp.cpp

@@ -6,6 +6,22 @@ ynl_socket::ynl_socket(const ynl_family& family, struct ynl_error* err) {
   sock_ = ynl_sock_create(&family, err);
 }
 
+ynl_socket::ynl_socket(ynl_socket&& other) noexcept : sock_(other.sock_) {
+  other.sock_ = nullptr;
+}
+
+ynl_socket& ynl_socket::operator=(ynl_socket&& other) noexcept {
+  if (this == &other)
+    return *this;
+
+  if (sock_)
+    ynl_sock_destroy(sock_);
+
+  sock_ = other.sock_;
+  other.sock_ = nullptr;
+  return *this;
+}
+
 ynl_socket::~ynl_socket() {
   if (sock_) {
     ynl_sock_destroy(sock_);

lib/ynl.hpp

@@ -14,6 +14,13 @@ namespace ynl_cpp {
 class ynl_socket {
  public:
   explicit ynl_socket(const ynl_family& family, ynl_error* err = nullptr);
+
+  ynl_socket(const ynl_socket&) = delete;
+  ynl_socket& operator=(const ynl_socket&) = delete;
+
+  ynl_socket(ynl_socket&& other) noexcept;
+  ynl_socket& operator=(ynl_socket&& other) noexcept;
+
   ~ynl_socket();
 
   operator bool() const {