Error parsing '+12345' as a float

[TD22057]

Version 1.1.2

#include <iostream>
#include <string_view>
#include <cstdio>
#include <scn/scn.h>

int main()
{
   const char* s = "+12345";
   std::string_view sv( s );
   
   double x;
   auto r = scn::scan( sv, "{}", x );
   if ( r ) std::cout << "scn: got: " << x << "\n";
   else std::cout << "scn: error: '" << r.error().msg() << "'\n";

   if ( sscanf( s, "%lf", &x ) == 1 ) std::cout << "scanf: got: " << x << "\n";
   else std::cout << "scanf: error\n";
         
   return 0;
}

yields:

scn: error: 'fast_float'
scanf: got: 12345

IMO this should work and return 12345. It's also a bit annoying that the error message just says "fast_float" instead of indicating what the problem is. Obviously I can guess what the problem is but when this is embedded in a larger application the user will have no idea what fast_float means.

[ilynxy]

According to https://github.com/fastfloat/fast_float and https://en.cppreference.com/w/cpp/utility/from_chars a leading '+' sign is forbidden.
IMO, leading '+' sign should be parsed with scnlib.

[TD22057]

Fair enough.

Is there any chance the error message could be improved? I'd be happy to help but the level of template programming used is more than I'm used to at least without some direction.

[eliaskosunen]

This works properly in v2, and is now also fixed properly in the latest master. Thanks for reporting!