An unexpected warning (trigraph)

[Robert Lipe]

Ryszard Kabatek wrote:

> x.cc:3:24: warning: trigraph ??> ignored
> x.cc: In function `int main()':
> x.cc:3: warning: unused variable `const char*str'
> 
> int main()
> {
>   const char* str = "<???>";
> }

Trigraphs are part of standard C and presumably standard c++.  They 
provide a way of representing characters not present on all keyboards.
(Think international keyboards, in particular.)

See invoke.texi and search for trigraph.

Mostly they serve to head-screw programmers...

RJL