Oleg Abrosimov wrote:
Alexander Nasonov:
in the "Lexical Conversion Library Proposal for TR2" (N1973) proposal Kevlin Henney and Beman Dawes states:
"Since either the source or target are usually strings, why not provide separate to_string(x) and string_to<t>(x) functions?
The source or target isn't always a string. Furthermore, the from/to idea cannot be expressed in a simple and consistent form. The illusion is that they are easier than lexical_cast because of the name. This is theory. The practice is that the two forms, although similarly and symmetrically named, are not at all similar in use: one requires explicit provision of a template parameter and the other not. This is a simple usability pitfall that is guaranteed to catch experienced and inexperienced users alike -- the only difference being that the experienced user will know what to do with the error message."
for me it is reasonable enough to require a symmetric usage of from_string/string_from functions I've proposed.
Well, I can buy into the idea that the target is always a 'string'. And frankly I've never used any other sort of target/source for these kinds of conversion. But your're still not responding to the core of my question. The problem is "what's a string"? Some possibilities: std::wstring std::string std::basic_string<uchar> //some sort of unicode string std::vector<char> //and variants thereof sti::rope jeffs_really_cool_string_class // ;-) I think even if the plan is to limit to 'a string' you will need to support these sort of options. Which means you need a second templat argument. Which probably means you need to clearly define the concept of a string w.r.t these conversions. And perhaps that's how it differentiates from lexical_cast. That is lexical_cast requires Target == InputStreamable, DefaultConstructable and Source == OutputStreamable. What are your concept requirements? Jeff