@@ -26,6 +26,7 @@ struct conversation_result {

 class conversation_ifc

 {

 public:

+    virtual ~conversation_ifc() {}

     virtual conversation_result initiate (const pam_request &request)

     {

         return { "", "" };

@@ -19,6 +19,7 @@ class fstreams_ifc

 {

 public:

     typedef std::shared_ptr<std::istream> pstream;

+    virtual ~fstreams_ifc() {}

     virtual pstream open_fstream (const std::string &file_path)

     {

         return pstream (new std::istringstream (""));

@@ -18,6 +18,7 @@

 class pam_ifc

 {

 public:

+    virtual ~pam_ifc() {}

     virtual int get_conv (pam_handle *handle, const pam_conv **out)

     {

         return PAM_SERVICE_ERR;

@@ -18,6 +18,7 @@

 class pwd_ifc

 {

 public:

+    virtual ~pwd_ifc() {}

     virtual int getpwnam_r (const char *user_name, passwd *out, char *buffer,

                             size_t buffer_sz, passwd **result)

     {

@@ -19,6 +19,7 @@

 class sys_syslog_ifc

 {

 public:

+    virtual ~sys_syslog_ifc() {}

     virtual void openlog (const char *ident, int logopt, int facility) {}

     virtual void vsyslog (int priority, const char *message, va_list args) {}

     virtual void closelog() {}

@@ -19,6 +19,7 @@

 class unistd_ifc

 {

 public:

+    virtual ~unistd_ifc() {}

     virtual long int sysconf (int name)

     {

         return -1;