Re: [Boost-users] [Spirit] Qi int_parser rejecting a negative signed std::intmax_t

Subject: Re: [Boost-users] [Spirit] Qi int_parser rejecting a negative signed std::intmax_t
From: Gavin Lambert (boost_at_[hidden])
Date: 2018-11-12 22:43:06

On 13/11/2018 05:27, Michael Powell wrote:
> Oops, my mistake. An error in one of the rules. Fixed it, and can
> demonstrate that negative values do not seem to parse correctly:
> 
> http://coliru.stacked-crooked.com/a/370b6aa5c167434b

Hex and octal literals produce unsigned values.  You need to put those 
into a uintmax_t, not an intmax_t.

FWIW, you can still use an intmax_t in your AST if you want, as the 
automatic attribute conversion will permit the twos-complement 
conversion (though it might annoy some sanitisers).

         hex_val %= no_case["0x"] >> uint_parser<std::uintmax_t, 16>{};
         oct_val %= "0" >> uint_parser<std::uintmax_t, 8>{};
         dec_val %= int_parser<ast::int_t, 10>{};

If you feel especially enthused, you can use 
std::make_unsigned_t<ast::int_t> instead.