cond7.c

this is a gcc file, you can download it and learn its usetility, for further detail please look at t

// Build don't link:
// 
// Copyright (C) 2001 Free Software Foundation, Inc.
// Contributed by Nathan Sidwell 24 Jul 2001 <[e-mail]>

// Bug 3416. We left some unchecked overloaded functions lying around.

struct X
{
  void operator << (int);
  void operator << (float);
};

void OVL1 (int);
void OVL1 (float);

void OVL2 (int);
void OVL2 (float);

X x;

void foo (bool a)
{
  x << (a ? OVL1 : OVL2);	// ERROR - incomplete type
  a ? OVL1 : OVL2;              // ERROR - incomplete type
}