Private `auto_ptr` field in classes without copy constructors or copy assignment operators.

I am now testing my new linter for checking smart pointer errors, and I have found something in your repo. Some of the classes declare a private auto_ptr field without defining a copy constructor or a copy assignment operator, which will cause the auto_ptr field becomes nullptr when it is copied. And this may cause a null pointer dereference problem when using the field after the object has been copied.
One solution to this issue is to declare both the copy constructor and the copy assignment operator to be deleted to prevent their objects being copied. Just like what is implicitly done when using unique_ptr.
I did not read all your code in your repo, but only reviewed the classes related to my reports. Therefore, I am not very sure whether my reports will really cause a crush. However, I think these reports worth being paid attention to.

Here are the reported classes:

cppcms/src/applications_pool.cpp

Line 399 in 270634e

class legacy_sync_pool : public application_specific_pool {

cppcms/src/cache_storage.cpp

Line 122 in 270634e

class mem_cache : public base_cache {

cppcms/booster/lib/aio/src/io_service.cpp

Line 114 in 270634e

class event_loop_impl {

cppcms/booster/lib/locale/src/icu/formatter.cpp

Line 153 in 270634e