Vladimir Prus wrote:
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.
The problem I find more concerning is implicit conversions caused by typo in operators s = format("name=%1 processed") % s1 + s2; if format is convertible to string, the type of s2 here might be such that this line compiles (e.g. s2 of type string), so such typos could go unnoticed for a while.. My opinion was it's safe to use operators for format as long as it is not implictly-convertible. it's true that using a str free function can be a nuisance. -- Samuel