Why having assert before main() causing compilation error? : Why assert is causing compilation error if I use it before main() call ?  
It causes compilation error (Syntax error):  

***"test.cpp:4:8: error: expected ')' before numeric constant"***


    #include <stdio.h>
    #include <assert.h>
    
    assert(0); //If I comment assert from here, then it compiles fine.
    
    int main()
    {
      assert(0);
      return 0;
    }

