Martin Bonner wrote:
While it's generally considered a bad practice to provide implicit conversions, I think it would be good to provide such a conversion for the boost::format class. [snip] Having been bit far too many times by bad implicit conversions, I would vote against such a change. I don't see why one shouldn't pass in a format object to a function (possibly for the function to add one argument to the format object).
And for implicit conversion to do any harm, you need to mistakenly pass boost::format to a function which takes std::string, right? In this case, boost::format will immediately throw and you'll detect the bug in no time.
I still think that providing a member function with(), rather than an operator % would have been better. Then one could write: string s = format("%1%").with(10).str(); which seems does seem neater than: string s = (format("%1%") % 10).str();
If we are to change boost::format, I would prefer to add such a member function than an implicit conversion.
The 'with' function (or, maybe 'arg', like in QString), can be indeed neater then parenthesis, though I still prefer string s = format("%1%") % 10; - Volodya