The below code does not give any fault/error/warning(although I think there might be some illegal memory access happening). Strangely, the size of the string being printed using 2 different methods(strlen and std::string.size() is coming out differently.
strlen(l_str.c_str()-> is giving the size as 1500, whereas, l_str.size()-> is giving the size as 0.
#include <string.h>
#include <string>
#include <stdio.h>
#include<iostream>
using namespace std;
void strRet(void* data)
{
char ar[1500];
memset(ar,0,1500);
for(int i=0;i<1500;i++)
ar[i]='a';
memset(data,0,1500); // This might not be correct but it works fine
memcpy(data,ar,1500);
}
int main()
{
std::string l_str;
cout<<endl<<"size before: "<<l_str.length();
int var=10;
strRet((void *)l_str.c_str());
printf("Str after call: %s
",l_str.c_str());
cout<<endl<<"size after(using strlen): "<<strlen(l_str.c_str());
cout<<endl<<"Size after(using size function): "<<l_str.size();
printf("var value after call: %d
",var);
return 0;
}
Please suggest, if I'm doing something which I'm not supposed to do!
Also, I wanted to know which memory bytes are being set to 0 when I do memset(data,0,1500);
? What I mean to ask is that if suppose, my string variable's starting address is 100, then does memset command sets the memory range [100,1600] as 0? Or is it setting some other memory range?