c++ - Difference between Copy Constructor and Assigment Operator -

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this question has answer here:

i'm having little trouble copy constructor.

i have class, contains 2 structures, , 2 pointers first structure ( let's i'm having linked list of first structure, , each contains linked list of second structure ). seem work fine. ...

when make instance of class using copy constructor ( deep copy, every element copied, each instance has it's own linked lists ) using

myclass a,b; // operations b ( );

it works ok. then...

myclass a,b; // operations b = a;

also seems work, destructor goes amok, , tries free element multiple times, sending this:

* error in `./a.out': double free or corruption (!prev): 0x000000000258a540 *

along ==backtrace== , ==memory map==, ending killing program sigabrt signal.

so, when copy constructor works fine , present, wrong assignment? should override operator= ?

thanks

if not have defined assignment operator explicitly, obvious code broken. implicit assignment operator member-wise assignment of each data member assigned object. if have member variables e.g. live on heap standard implicit assignment operator not deep copy , copies pointer values.


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