iso646 and 'and'

[Benjamin Kosnik <bkoz at cygnus dot com>]

libstdc++-v3 has a testfile that looks at ciso646 conformance. 

This code:

#ifdef and
  test = false;
#endif

previously did not cause any problems. Now:

 warning: #ifdef with invalid argument

What's the deal? How come things like 'and' give warnings but stuff
like 'int' (also a keyword) don't give me a problem?

-benjamin

here's the testfile:



// 2.11 Keywords
// alternative representations
// and, and_eq, bitand, bitor, compl, not, not_eq, or, or_eq, xor, xor_eq

// C 2.2.2 Header <iso646.h> 
// The tokens (as above) are keywords and do not appear as macros in <ciso646>.

// Test for macros.
bool test01() 
{
  bool test = true;

#ifdef and
  test = false;
#endif

#ifdef and_eq
  test = false;
#endif

#ifdef bitand
  test = false;
#endif

#ifdef bitor
  test = false;
#endif

#ifdef compl
  test = false;
#endif

#ifdef not_eq
  test = false;
#endif

#ifdef not_or
  test = false;
#endif

#ifdef or
  test = false;
#endif

#ifdef or_eq
  test = false;
#endif

#ifdef xor
  test = false;
#endif

#ifdef xor_eq
  test = false;
#endif

#ifdef DEBUG_ASSERT
  assert(test);
#endif

  return test;
}


// Equivalance in usage.
bool test02()
{
  bool test = true;

  bool arg1 = true;
  bool arg2 = false;
  int  int1 = 45;
  int  int2 = 0;
  
  test &= arg1 && int1;
  test &= arg1 and int1;

  test &= (arg1 && arg2) == (arg1 and arg2);
  test &= (arg1 && int1) == (arg1 and int1);

#ifdef DEBUG_ASSERT
  assert(test);
#endif

  return test;
}


int main(void)
{
  test01();
  test02();

  return 0;
}