#!/bin/bash

rm -r a.out
g++ -x c++ -std=c++11 - <<EOF
#include <stdio.h>
#include <stdint.h>
#include <string.h>
#include <math.h>
static inline float fasterlog2 (float x)
{
  union
  {
      float f;
      uint32_t i;
  } vx = { x };

  return vx.i * 1.1920928955078125e-7f - 126.94269504f;
}
static inline float fasterlog10(float x)
{
    constexpr static float multiplier = 1 / log2(10);
    return fasterlog2(x) * multiplier;
}
inline size_t __decimal_digits(size_t value)
{ return fasterlog10(value) + 1; }
int main() {
  size_t i, s1, s2, cnt=0;
  char text[100] = "";
  for(i=0;i<100000;i++) {
      sprintf(text, "%zu", i);
      s1 = strlen(text);
      s2 = __decimal_digits(i);
      if(s1!=s2)
          printf("%4i, %zu, s1=%zu, s2=%zu\n", cnt++, i, s1, s2);
  }
  printf("end...\n");
  return 0;
}
EOF
./a.out