Convert MAC address std::string into uint64_t

uint64_t string_to_mac(std::string const& s) {
    unsigned char a[6];
    int last = -1;
    int rc = sscanf(s.c_str(), "%hhx:%hhx:%hhx:%hhx:%hhx:%hhx%n",
                    a + 0, a + 1, a + 2, a + 3, a + 4, a + 5,
                    &last);
    if(rc != 6 || s.size() != last)
        throw std::runtime_error("invalid mac address format " + s);
    return
        uint64_t(a[0]) << 40 |
        uint64_t(a[1]) << 32 | ( 
            // 32-bit instructions take fewer bytes on x86, so use them as much as possible.
            uint32_t(a[2]) << 24 | 
            uint32_t(a[3]) << 16 |
            uint32_t(a[4]) << 8 |
            uint32_t(a[5])
        );
}

My solution (requires c++11):

#include <string>
#include <cstdint>
#include <algorithm>
#include <stdlib.h>


uint64_t convert_mac(std::string mac) {
  // Remove colons
  mac.erase(std::remove(mac.begin(), mac.end(), ':'), mac.end());

  // Convert to uint64_t
  return strtoul(mac.c_str(), NULL, 16);
}

Use sscanf:

std::string mac = "00:00:12:24:36:4f";
unsigned u[6];
int c=sscanf(mac.c_str(),"%x:%x:%x:%x:%x:%x",u,u+1,u+2,u+3,u+4,u+5);
if (c!=6) raise_error("input format error");
uint64_t r=0;
for (int i=0;i<6;i++) r=(r<<8)+u[i];
// or:  for (int i=0;i<6;i++) r=(r<<8)+u[5-i];