#include <iostream>
#include <regex>
using namespace std;
string pattern = "([a-z]+).\\1";
string str = "top-topcoder|coder";

re_pattern_buffer buffer;
  char map[256];

buffer.translate = 0;
buffer.fastmap = map;
buffer.buffer = 0;
buffer.allocated = 0;

re_set_syntax(RE_SYNTAX_POSIX_EXTENDED);
const char* status = re_compile_pattern(pattern.c_str(),pattern.size(),&buffer); 
if (status) {
    cout << "Error: " << status << endl;
}
re_compile_fastmap(&buffer);

struct re_registers regs;
int ofs = 0;
if (re_search(&buffer,str.c_str(),str.size(),0,str.size(),&regs)!=-1) {
  cout << "Match " 
  cout << str.substr(regs.start[0],regs.end[0]-regs.start[0])
  cout << " found starting at: "
  cout << regs.start[0]
  cout << " and ending at "
  cout << regs.end[0]
  cout << endl;
} else {
  cout << "Match not found."
  cout << endl;
}
regfree(&buffer);  

int main()
{
	return 0;
}