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Consider this code: #include <memory> #include <iostream> class A { public: A(int data) : data_(data) { std::cout << "A(" << data_ << ")" << std::endl; } ~A() { std::cout << "~A()" << std::endl; } void a() { std::cout << data_ << std::endl; } private: int data_; }; class B { public: B(): a_(new A(13)) { std::cout << "B()" << std::endl; } ~B() { std::cout << "~B()" << std::endl; } std::function<void()> getf() { return [=]() { a_->a(); }; } private: std::shared_ptr<A> a_; }; int main() { std::function<void()> f; { B b; f = b.getf(); } f(); return 0; } Here it looks like I'm capturing a_ shared pointer by value, but when I run it on Linux (GCC 4.6.1), this is printed: A(13) B() ~B() ~A() 0 Obviously, 0 is wrong, because A is already destroyed. It looks like this is actually captured and is used to look up this->a_ . My suspicion is confirmed when I change the capture list from [=] to [=,a_] . Then the correct output is printed and the lifetime of the objects is as expected: A(13) B() ~B() 13 ~A() The question: Is this behaviour specified by the standard, implementation-defined, or undefined? Or I'm crazy and it's something entirely different?

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