Alexander Nasonov:
Jeff Garland wrote:
Oleg Abrosimov wrote:
and if one wants to be very modern ;-) but doesn't concern about symmetry in from_string/string_from usage : double d = 2 + from_string<double>("10.2"); This is fine too. Perfect symmetry isn't really needed.
I agree with Jeff. The string_from differs from the from_string in a fundamenal way: the former _accepts_ arguments of different types while the latter _returns_ different types. You can't overload on return types in C++. Why do you require a symmetry for asymmetrical functions?
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. Best, Oleg Abrosimov.