+ 4

How does the dead monkey shows its tail?

class Monkey { public: int taleLength = 3; void showTale() { cout << "Monkey says: 'My tale is " << taleLength << "m' \n"; } ~Monkey() { cout << "Monkey was killed by a poacher :(\n"; } }; int main() { Monkey* p; { Monkey Jack; p = &Jack; } p->showTale(); system("pause"); } Output: Monkey was killed by a poacher :( Monkey says: 'My tale is 3m' Destructor was called, but why does the Jack still exist?

17th Oct 2017, 2:16 PM
Макс Елисеев (WMax)
Макс Елисеев (WMax) - avatar
2 ответов
+ 3
Poor old Jack still exists and is valid because the stack has not been cleaned yet, nor has it been overwritten. Let's look at the partial disassembly: #stack allocation and setting up stack frame push rbp mov rbp, rsp sub rsp, 16 #Creating Jack on the stack lea rdi, [rbp - 16] call Monkey::Monkey() #Get the address of Jack lea rdi, [rbp - 16] #Store it in p mov QWORD PTR [rbp-8], rax #Call destructor call Monkey::~Monkey() #Call showTale, p is still pointing to valid stack memory, so this will work. mov rdi, qword ptr [rbp - 8] call Monkey::showTale() #deallocate stack and return 0 xor eax, eax add rsp, 16 pop rbp ret
17th Oct 2017, 3:07 PM
aklex
aklex - avatar
+ 6
I'm sorry, I don't know. But I definitely had to say this question's title made me laugh
17th Oct 2017, 2:28 PM
Dapper Mink
Dapper Mink - avatar