eedb/share/include/tao/json/external/pegtl/internal/must.hh
2017-02-26 09:32:45 +01:00

50 lines
1.5 KiB
C++

// Copyright (c) 2014-2015 Dr. Colin Hirsch and Daniel Frey
// Please see LICENSE for license or visit https://github.com/ColinH/PEGTL/
#ifndef TAO_CPP_PEGTL_INTERNAL_MUST_HH
#define TAO_CPP_PEGTL_INTERNAL_MUST_HH
#include "seq.hh"
#include "raise.hh"
#include "skip_control.hh"
namespace tao_json_pegtl
{
namespace internal
{
// The general case simply applies must<> to each member of the
// 'Rules' parameter pack individually, below is the specialization
// which implements the case for a single rule.
template< typename ... Rules >
struct must
: seq< must< Rules > ... > {};
// While in theory the implementation for a single rule could
// be simplified to must< Rule > = sor< Rule, raise< Rule > >, this
// would result in some unnecessary run-time overhead.
template< typename Rule >
struct must< Rule >
{
using analyze_t = typename Rule::analyze_t;
template< apply_mode A, template< typename ... > class Action, template< typename ... > class Control, typename Input, typename ... States >
static bool match( Input & in, States && ... st )
{
if ( ! Control< Rule >::template match< A, Action, Control >( in, st ... ) ) {
raise< Rule >::template match< A, Action, Control >( in, st ... );
}
return true;
}
};
template< typename ... Rules >
struct skip_control< must< Rules ... > > : std::true_type {};
} // namespace internal
} // namespace tao_json_pegtl
#endif