Re: [boost] undefined behaviour in tuple_io.hpp (bug)(patch)

From: Jonathan Wakely (cow_at_[hidden])
Date: 2005-08-25 05:42:20

Rupert Kittinger wrote:

> In the tuple_io.hpp header, there seems to be a slight problem in
> extract_and_check_delimiter(). The following snippet is problematic:
> 
> char c;
> if (is_delimiter) {
>     is >> c;
>     if (c!=d) {
>       is.setstate(std::ios::failbit);
>     }
> }
> 
> If c cannot be read because is.eof(), the result of c!=d is undefined.

IMHO the fix is neater as:

     if (is>>c && c!=d)

basic_ios::operator void*() exists to support this syntax rather than
explicitly testing the state with good(), fail() etc.

jon