title: Include specific function from a header file into the code in c++
body: <p>In python, one can import specific feature-sets from different modules, rather than importing the whole file<br></p>
  
  <p>ex:</p>
  
  <p>Instead of using <code>import math</code> and using <code>print math.sqrt(4)</code>, importing the function directly:</p>
  
  <pre><code>from math import sqrt
  print sqrt(4)
  </code></pre>
  
  <p>And it works just fine.<br></p>
  
  <hr>
  
  <p>Where as in <code>C</code> and <code>C++</code>, one has to include the whole header file to be able to use just one function that it provides. Such as, in C++</p>
  
  <pre><code>#include&lt;iostream&gt;
  #include&lt;cmath&gt;
  int main(){
      cout&lt;&lt;sqrt(4);
      return 0;
  }
  </code></pre>
  
  <p><code>C</code> code will also be similar (not same).</p>
  
  <hr>
  
  <p>Is it possible that just like as it was in case of python, one can include just one function from a header file into their program?<br>
  ex: including just the <code>sqrt()</code> function from <code>cmath</code>?
  <br><br>Could it be done?</p>