Disable the last two throws.  They're for error reporting and should be replaced with calls to an error delegate later.
parserlib now compiles (and works!) with no RTTI or exceptions.
Added README for the refactoring.
Delete a method that should not be called.
Constify dump()
Rename private expression classes.
Add user literals for string and char expressions.
Remove state from rules.
Big cleanup of expression classes.  Still some ugly syntax for rules required.
Cleanups and syntax improvements.
Remove the parse proc field from the rule.
Whitespace / indenting cleanup.
Update todo list.
Remove old line accidentally left in.
Remove parserlib_private.
Replace ->this_ptr() with std::addressof().
Use std::function instead of raw function pointers.
This allows lambdas to be used as parsing callbacks.
Replace parse proc templated static with lambda.
Another item for the TODO list
Stop ast_node from being a subclass of input_range.
AST nodes should be allowed to retain the source location information if they need it, but not compelled to do so.
Add parsing delegate providing the binding from rules to values.