Synopsis

template <class P, class S>
struct debug_parsing_error
{
  debug_parsing_error();
};

This is a template class.

Description

Utility to debug errors generated by a compile-time parser. An instance of the instantiated template class has to be created and initialised using the default constructor. When parsing the input string using the parser generates an error, the default constructor of debug_parsing_error prints the error message to the standard output at run-time and calls exit.

	Note
	Note that more powerful debugging utilities, like Metashell are also available.

Header

#include <boost/metaparse/debug_parsing_error.hpp>

Expression semantics

For any p compile-time parser and s compile-time string

debug_parsing_error<p, s>()

Tries to parse s using p at compile-time. At run-time the constructor prints the result of parsing to the standard output and calls exit.

Example

#include <boost/metaparse/debug_parsing_error.hpp>
#include <boost/metaparse/int_.hpp>
#include <boost/metaparse/string.hpp>

#include <type_traits>

using namespace boost::metaparse;

debug_parsing_error<int_, BOOST_METAPARSE_STRING("not an int")> do_debugging;

int main() {}

By running the compiled executable you get the following:

Compile-time parsing results ---------------------------- Input text: not an int

Parsing failed: line 1, col 1: Digit expected