title: 'to_string' is not a member of 'std'
body: <p>i compile the project with the mingw and the project is cool compiler .
  this is a part of my code</p>
  
  <pre><code>#include "astnodecodegenerator.hpp"
  #include "utility.hpp"
  #include "constants.hpp"
  #include &lt;string&gt;
  #include &lt;cmath&gt;
  #include &lt;sstream&gt;
  #include &lt;stack&gt;
  </code></pre>
  
  <p>.
  .
  .
  .</p>
  
  <pre><code>void AstNodeCodeGenerator::visit(StringConst&amp; str) 
  { 
      emit_la("a0", (std::string("str_const") + std::to_string(stringtable().get_idx(str.token.get_val()))).c_str());
  }
  
  void AstNodeCodeGenerator::visit(IntConst&amp; int_const) 
  {
      emit_la("a0", (std::string("int_const") + std::to_string(inttable().get_idx(int_const.token.get_val()))).c_str());
  }
  </code></pre>
  
  <p>the error is:</p>
  
  <pre><code>error :'to_string' is not a member of 'std' emit_la&lt;"a0",&lt;std::string(("str_const") + std::to_string(stringtable().get_idx(str.token.get_val()))).c_str());
  </code></pre>