title: Function to_hstring from std.textio is not working [VHDL]
body: <p>I tried to run some code from Stack Overflow (<a href="https://stackoverflow.com/questions/37879954/how-to-write-an-integer-to-stdout-as-hexadecimal-in-vhdl">How to write an integer to stdout as hexadecimal in VHDL?</a>) and it turned out that <strong>to_hstring</strong> doesn't work (Even though <strong>std</strong> library is standard for VHDL). I am using Active-HDL 9.1 (probably the root of the problem is in the old version of Active-HDL). I'm new to VHDL coding, so I believe I missed something obvious there. Thanks for any help!</p>
  <p>Here is the sample code:</p>
  <pre><code>library ieee,std;
      use std.textio.all;
      use ieee.std_logic_1164.all;
      use ieee.numeric_std.all;
  
  entity min is
  end min;
  
  architecture behav of min is
  begin
      process is
      begin
          report &quot;i = 0x&quot; &amp; to_hstring(to_signed(16, 32));
      end process;
  end behav; 
  </code></pre>
  <p>And output of the compiler:
  <a href="https://i.stack.imgur.com/3wvoN.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/3wvoN.png" alt="enter image description here" /></a></p>