.. efun:: string set_bit(string str, int n)

  Return the new string where bit :arg:`n` is set in string :arg:`str`. Note that the old string :arg:`str` is not modified.

  Each character contains 6 bits. So you can store a value between 0 and 63 in one character (2^6=64). Starting character is the blank :char:`SPACE` which has the value 0. The first charcter in the string is the one with the lowest bits (0-5).

  The new string will automatically be extended if needed.

  .. usage::

    ::

      string s;
      s=set_bit("?",5);

    Because "?" has a value of 31 the variable s will now contain the character "_" which is equal to 63 (31+2^5=63)::

      string s;
      s=set_bit("78",3);
      s=set_bit(s,8);
      //s will now contain the string "?<".

  .. seealso:: :efun:`clear_bit`, :efun:`last_bit`, :efun:`next_bit`, :efun:`test_bit`, :efun:`count_bits`, :efun:`and_bits`, :efun:`or_bits`, :efun:`xor_bits`, :efun:`invert_bits`, :efun:`copy_bits`