# File lib/active_support/json/backends/okjson.rb, line 342
    def ucharenc(a, i, u)
      case true
      when u <= Uchar1max
        a[i] = (u & 0xff).chr
        1
      when u <= Uchar2max
        a[i+0] = (Utag2 | ((u>>6)&0xff)).chr
        a[i+1] = (Utagx | (u&Umaskx)).chr
        2
      when u <= Uchar3max
        a[i+0] = (Utag3 | ((u>>12)&0xff)).chr
        a[i+1] = (Utagx | ((u>>6)&Umaskx)).chr
        a[i+2] = (Utagx | (u&Umaskx)).chr
        3
      else
        a[i+0] = (Utag4 | ((u>>18)&0xff)).chr
        a[i+1] = (Utagx | ((u>>12)&Umaskx)).chr
        a[i+2] = (Utagx | ((u>>6)&Umaskx)).chr
        a[i+3] = (Utagx | (u&Umaskx)).chr
        4
      end
    end