Roland Richter wrote:
Reece and fellow boosters,
I have a special interest in Output Formatters working together with lexical_cast. The idea is this:
Since lexical_cast internally uses a stringstream and its associated operators >> and <<, and since outfmt defines << and >> for STL containers, it should be possible to lexical_cast any STL container. ... the reverse "input" operation
boost::lexical_cast< std::vector<int> >( "[ 7, 9 ]" ); // throws bad_lexical_cast
fails. This is because lexical_stream turns off white space skipping, and outfmt uses "[ ", ", ", and " ]" (with all those nifty spaces) as default formatting.
The problem is that I can't pass any formatting options to lexical_stream at runtime. Hence, I'd like to propose that
a) either the default formatting of containers is changed to "[", ",", and "]", b) or a compile-time mechanism (macro? template magic?) should be provided to set the formatting.
I've made a noise about this in the past. I strongly believe that current lexical_cast behaviour does not play nice with existing stream operators (which are commonly written to assume whitespace is skipped). There's no good reason for that, and lexical_cast should not use the "noskipws" flag. - Volodya