c++ - Copy constructor causes memory leak -


i've checked this post, , tried suggestions mentioned, instead of getting memory leaks segmentation faults.

this code causes leak:

class recordwithkey : public varlengthrecord {      protected:         key* key; };  class key {      protected:         keytype keytype;         key* keys[2];  };  recordwithkey& recordwithkey::operator=(const recordwithkey& other) {     if (this != &other)     {         this->key = new key(*(other.key));         /* ... other code ... */     }     return *this; }  recordwithkey::~recordwithkey() {     delete(key);     key = null; }  key::~key() {     (unsigned int = 0; < key_types; i++)     {         delete(keys[i]);         keys[i] = null;     } }  key& key::operator =(const key& other) {     if (this != &other)     {         this->keytype= other.keytype;          for(unsigned int i=0;i<key_types;i++)             (*keys[i]) = (*other.keys[i]);     }     return (*this); }     recordwithkey::recordwithkey()     :varlengthrecord() {     key = null; }  recordwithkey::recordwithkey(const recordwithkey& other)     : varlengthrecord(other) {     key = new key(*(other.key)); }  key::key() {     this->keytype = type_string; //default type     this->keys[type_numeric]= new numerickey;     this->keys[type_string]= new stringkey; }   key::key(const key& other) {     this->keytype = other.keytype;     this->keys[type_numeric]= new numerickey;     this->keys[type_string]= new stringkey;      if (this->keytype == type_numeric)     {         int key;         other.get_key(key);         set_key(key); //there no "new" inside of     }     else if (this->keytype == type_string)     {         std::string key;         other.get_key(key);         set_key(key); //there no "new" inside of     } }

this report valgrind:

==15019== 8 bytes in 1 blocks indirectly lost in loss record 1 of 41 ==15019==    @ 0x402b9b4: operator new(unsigned int) (in /usr/lib/valgrind/vgpreload_memcheck-x86-linux.so) ==15019==    0x80673e6: key::key(key const&) (key.cpp:21) ==15019==    0x806b414: recordwithkey::recordwithkey(recordwithkey const&) (recordwithkey.cpp:20) ==15019==    0x805b8f6: __gnu_cxx::new_allocator<recordwithkey>::construct(recordwithkey*, recordwithkey const&) (in /project/tests/tests) ==15019==    0x805ba55: std::vector<recordwithkey, std::allocator<recordwithkey> >::_m_insert_aux(__gnu_cxx::__normal_iterator<recordwithkey*, std::vector<recordwithkey, std::allocator<recordwithkey> > >, recordwithkey const&) (vector.tcc:335) ==15019==    0x805b370: std::vector<recordwithkey, std::allocator<recordwithkey> >::push_back(recordwithkey const&) (stl_vector.h:834) ==15019==    0x806ff73: nodosecuencial::insertar(recordwithkey const&, std::vector<recordwithkey, std::allocator<recordwithkey> >&) (nodosecuencial.cpp:102) ==15019==    0x8059a8e: testnodosecuencial::test_nodo_sec_insertar_eliminar() (testnodosecuencial.cpp:200) ==15019==    0x8058400: testnodosecuencial::ejecutar() (testnodosecuencial.cpp:22) ==15019==    0x8076d91: main (tests.cpp:261)

any ideas? thanks!

your problem in copy assignment operator: this->key = new key(*(other.key)); leaks allocated key object.

the best c++-idiomatic solution not using newly allocated items. store key , keys attributes value , problem goes away.


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