constexpr __FILE__ hashing

constexpr_hash.cpp

#include <iostream>
using namespace std;

constexpr unsigned long long fnv_hash64_r(unsigned long long result, const char* string)
{
  return (*string == 0) ? result : fnv_hash64_r(1099511628211ULL * result ^ *string, string + 1);
}

constexpr unsigned long long fnv_hash64(const char* string)
{
  return fnv_hash64_r(14695981039346656037ULL, string);
}

constexpr auto this_file = fnv_hash64(__FILE__);

int main(int argc, char** argv)
{
  cout << hex << this_file << endl;
}