That's not my concern. My concern is that I don't think lexical_cast is a particularly good interface for its main uses, which could be thought of as "to-string" and "from-string."
Dave, I am not sure what you see wrong with lexical_cast interface. Could you elaborate? I am not using lexical_cast (due to throw, no default value and the def.ctor requirement). So, I still keep using the analog I wrote a while back and well before I ever heard of lexical_cast. Even though I wrote it independently, the interface happened to be very close: namespace aux { namespace string { template<class Type> std::string from (Type const&); template<class Type, class String> bool is (String const&) throw(); template<class Type, class String> Type to (String const&); template<class Type, class String> Type to (String const&, Type const&); } } That is, string str = aux::string::from(-1); int i1 = aux::string::to<int>(str); // throw int i2 = aux::string::to<int>(str, -1); // no throw As you can see it is pretty close to lexical_cast.
... I just don't think lexical_cast is the interface we need for most convenient string conversions.
It might be the case. However, I do not see any other practical suggestions that we could act on. Therefore, in the end we end up with nothing at all... again. That's been dragging for far too long.
... Maybe so, but I don't think lexical_cast is all that well-designed for convenience to begin with, and tacking on little convenience features isn't likely to yield a very clean interface.
I am not that concerned about the internal design as it can be worked on and improved without rush behind the interface. If it is the interface that is the issue, then let's look at it. Any suggestions? So far, I do not see people arguing against that proposed "extension" offering anything practical in return. That is not constructive as people end up with nothing at all. I am not counting the <optional> suggestion as it seems as an overkill and it still has the default-constructability requirement. Thanks, Vladimir.