std::shared_ptr<T>::~shared_ptr
From cppreference.com
< cpp | memory | shared ptr
~shared_ptr(); | ||
If *this owns an object and it is the last shared_ptr owning it, the object is destroyed through the owned deleter.
After the destruction, the smart pointers that shared ownership with *this, if any, will report a use_count() that is one less than its previous value.
[edit]Notes
Unlike std::unique_ptr, the deleter of std::shared_ptr is invoked even if the managed pointer is null.
[edit]Example
Run this code
#include <iostream>#include <memory> struct S { S(){std::cout<<"S::S()\n";} ~S(){std::cout<<"S::~S()\n";}struct Deleter {void operator()(S* s)const{std::cout<<"S::Deleter()\n"; delete s;}};}; int main(){auto sp =std::shared_ptr<S>{new S, S::Deleter{}}; auto use_count =[&sp](char c){std::cout<< c <<") use_count(): "<< sp.use_count()<<'\n';}; use_count('A');{auto sp2 = sp; use_count('B');{auto sp3 = sp; use_count('C');} use_count('D');} use_count('E'); // sp.reset();// use_count('F'); // would print "F) use_count(): 0"}
Output:
S::S() A) use_count(): 1 B) use_count(): 2 C) use_count(): 3 D) use_count(): 2 E) use_count(): 1 S::Deleter() S::~S()
[edit]See also
destroys a weak_ptr(public member function of std::weak_ptr<T>) |
