unique_ptr and base classes without a virtual destructor

[Fraser]

Here is a quote from cppreference.com: "If T is a derived class of some base B, then std::unique_ptr<t> is implicitly convertible to std::unique_ptr. The default deleter of the resulting std::unique_ptr will use operator delete for B, leading to undefined behavior unless the destructor of B is virtual."</t>

I suspect that cppcheck does not catch this undefined behaviour and it is not something a compiler warns about either.

[Daniel Marjamäki]

I suspect so too. Could you create a minimal example code? Do you have a Trac account? Then please feel free to create a ticket.

[Fraser]

I will put this on trac as well.

class Base {
public:
virtual ~Base()= 0;
Base() {
std::cout << "Base constructor" << '\n';
}
};

Base::~Base() {
std::cout << "Base destructor" << '\n';
}

class Base2 {
public:
~Base2();
Base2() {
std::cout << "Base2 constructor" << '\n';
}
};

Base2::~Base2() {
std::cout << "Base2 destructor" << '\n';
}

class Leaker :
public Base2 {
public:
~Leaker();
Leaker() {
std::cout << "Leaker constructor" << '\n';
}
};

Leaker::~Leaker() {
std::cout << "Leaker destructor" << '\n';
}

class NonLeaker :
public Base {
public:
~NonLeaker();
NonLeaker() {
std::cout << "NonLeaker constructor" << '\n';
}
};

NonLeaker::~NonLeaker() {
std::cout << "NonLeaker destructor" << '\n';
}

std::unique_ptr<base2> CreateLeaker() {
return std::make_unique<leaker>();
}</leaker></base2>

std::unique_ptr<base> CreateNonLeaker() {
return std::make_unique<nonleaker>();
}</nonleaker>

int _tmain(int argc, _TCHAR* argv[])
{
{
auto nl= CreateNonLeaker();
}
{
auto l= CreateLeaker();
}
return 0;
}