title: C/C++ best practice to eliminate Wconversion warnings
body: <p>I find the <code>-Wconversion</code> gcc/clang option is very useful for finding some code errors. But there are also many cases where the implicit type conversions are safe.<br>
  For example:  </p>
  
  <pre><code>double a_small_double = 3.5;
  /*implicitly convert double to int*/
  int i = floor(a_small_double);
  
  int len = 3;
  /*implicitly convert int to size_t*/
  double *p = (double*)malloc(len*sizeof(double));
  </code></pre>
  
  <p>Should I add an explicit type conversion every time(which is not concise at all), or just ignore them? </p>