Convenient printf usage in C++ via snprintf wrapping

#include <iostream> // Required for main

#include <string>
#include <vector>
#include <cstdio>

/**
 * Creates a string from a printf format and the arguments by wrapping snprintf.
 * Uses on-stack buffer under 100 total length, allocates on heap otherwise.
 */
template<typename ... Params>
std::string pformat(char const *fmt, Params&& ... args)
{
  const int BS = 100;
  char buf[BS];
  int cap = std::snprintf(buf, BS, fmt, std::forward<Params>(args)...);
  if(cap<BS)
    return std::string(buf, cap);
  std::vector<char> out(cap+1);
  std::snprintf(out.data(), cap+1, fmt, std::forward<Params>(args)...);
  return std::string(out.data(), cap);
}

int main()
{
  std::string x = pformat("Hill #%d, winner %s and %d", 1234, "Superman", 4321);
  std::cout << "--->|" << x << "|<---" << std::endl;
  std::cout << x.size() << std::endl;
  std::string y = pformat("This will be surely a little bit longer than 100"
    " characters which is the limit for another strategy in pformat():"
    " Hill #%d, winner %s and %d", 1234, "Superman", 4321);
  std::cout << "--->|" << y << "|<---" << std::endl;
  std::cout << y.size() << std::endl;
  return 0;
}