title: Mingw doesn't compile due to "'isblank' was not declared in this scope" error
body: <p>I try to compile &amp; link the following program with mingw. When I use the default version it works well. But when I use c++11 version it doesn't compile and gives me the following error <code>newfile.cpp:22:18: error: 'isblank' was not declared in this scope</code>.
  for testing the following program it's enough to call the <code>_isblank</code> function in main.</p>
  
  <p>For compiling the Netbeans 8.0.2 uses <code>g++    -c -g -Wall -std=c++11 -MMD -MP -MF "build/Debug/MinGW_1-Windows/newfile.o.d" -o build/Debug/MinGW_1-Windows/newfile.o newfile.cpp</code>.</p>
  
  <p>The mingw version is 4.8.1 and everything is configured well(Default).</p>
  
  <p>I tried by adding/removing namespace std. The problem seems to be in cctype header! But I wonder how to solve it. The project will have to be compiled with g++ on linux! Will these problems remain?</p>
  
  <pre><code>#include &lt;cstdlib&gt;
  #include &lt;cctype&gt;
  #include &lt;fstream&gt;
  #include &lt;sstream&gt;
  #include &lt;string&gt;
  #include &lt;iostream&gt;
  #include &lt;map&gt;
  #include &lt;functional&gt;
  #include "newfile.h"
  
  using namespace std;
  conf_info_t CONF_INFO;
  
  #define CONF_FILE_ADDRESS "confs.txt"
  //
  //typedef std::map&lt;std::string, std::function&lt;void (const std::string&amp;)&gt;&gt; confMap_t;
  //confMap_t confMap;
  
  int _isblank(int c){
      return isblank(c);
      //return c == ' ' || c == '\t';
  }
  </code></pre>