title: Is there a way to make a c++ compiler flag as default
body: <p>Just like we specify input flags in the settings of the project in Xcode</p>
  
  <p>Can I make few flags like -O3 or -fopenmp as default flags in command line when I use Terminal.<br>
  So that I dont have to type them everytime I compile some c++ fies. Is there a file in the installed gcc or C++ that I can edit to make them default.
  Please let me know 
  thanks</p>