It looks like the static "apply" will not allow to pass additional conversion parameters, except by resorting to Boost.Bind or something similar. Why not simply provide operator() in the converter?
Yes, I think it's a good idea. Will do. the 'apply' was a quick hack anyway.
Then having support of Boost.Parameter, we could pass some customization to the converter constructor:
std::transform( integers.begin(), integers.end(), std::back_inserter(strings), converter<int, string>(radix_ = 16, uppercase_ = true));
I looked a Boost.Parameter and will certainly try using it somewhere. My hesitation with it for boost::convert is I am under impression that the set of acceptable parameters (radix_, etc.) has to be predefined and therefore cannot be extended by the user when formatting like "convert(str) >> std::hex" seems more flexible. V.