The tutorial is still using the MPLLIBS_STRING and MPLLIBS_DEFINE_ERROR macros instead of their BOOST_xxx counterpart. This should be fixed if the library makes it in.

Hi. I am using boost::metaparse::string for value-based metaprogramming.
For convenience, I created a macro for myself:

#ifdef BOOST_METAPARSE_MAKE_STRING
#error BOOST_METAPARSE_MAKE_STRING already defined
#endif
#define BOOST_METAPARSE_MAKE_STRING(S) (BOOST_METAPARSE_STRING(S){})

This macro allows me to write such statements succinctly and without unnecessary parentheses:

field<int, (name=BOOST_METAPARSE_MAKE_STRING("id"))> index;
field<std::string, (name=BOOST_METAPARSE_MAKE_STRING("user"))> username;

In modern C++(example above is C++17), the value-based metaprogramming approach is very often used. I believe that this macro will be useful not only for me. Why not add it to the library?

Because I am almost sure this is not documented or even missing, this question is the same as my SO question https://stackoverflow.com/q/59844966/3537677 :

Is there a way to separate the to be parsed DSL into a file? Like instead of

using input = BOOST_METAPARSE_STRING("DSL content");

I want to use something like

using input = BOOST_METAPARSE_STRING(#include "dsl.txt");

with dsl.txt containing

DSL content

?