iso646 and 'and'

[Gabriel Dos Reis]

Benjamin Kosnik <bkoz@cygnus.com> writes:

| 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

There are not keyword but digraphs,  thus invalid operands of #ifdef or
#define.  

-- Gaby