c++ - Debug Error when invoking destructor with delete -

i have following code :

#include <iostream> using namespace std; class mystring { private:     char* buffer;  public:     mystring(const char* initialinput){         if(initialinput){             buffer = new char[strlen(initialinput + 1)];             strcpy_s(buffer, strlen(initialinput) + 1, initialinput);         } else { buffer = null; }     }     ~mystring(){ if(buffer){ delete buffer; } }      int getlength(){ return strlen(buffer); }     const char* getstring() { return buffer; } };  void usemystring(mystring const& input) {     cout << "string buffer in mystring " << input.getlength() << " characters long." << endl;     cout << "buffer contains: " << input.getstring() << endl; }  int main(){     mystring sayhello("hello string class");     usemystring(sayhello);      return 0; } 

http://i.stack.imgur.com/pl4nz.jpg

two objects different char* buffer created. however, unable delete buffer. if comment out

    if (buffer != null)         delete buffer; 

the program run through. why happen?

if allocate memory buffer = new char[length] should free memory delete[] buffer;

but there other problems in code. why don't want use std::string ? more efficient...

i can't compile code either (i don't use windows) have issues strcpy_s , strlen , there issues type conversion.