84 lines
2.7 KiB
C++
84 lines
2.7 KiB
C++
#ifndef RFL_INTERNAL_REMOVEFIELDS_HPP_
|
|
#define RFL_INTERNAL_REMOVEFIELDS_HPP_
|
|
|
|
#include <algorithm>
|
|
#include <tuple>
|
|
#include <type_traits>
|
|
|
|
#include "../NamedTuple.hpp"
|
|
#include "../define_named_tuple.hpp"
|
|
#include "StringLiteral.hpp"
|
|
|
|
namespace rfl {
|
|
namespace internal {
|
|
|
|
/// Recursively builds a new NamedTuple type from the FieldTypes, leaving out
|
|
/// the field signified by _name.
|
|
template <class _OldNamedTupleType, StringLiteral _name,
|
|
class _NewNamedTupleType, int _i>
|
|
struct remove_single_field;
|
|
|
|
/// Special case - _i == 0
|
|
template <class _OldNamedTupleType, StringLiteral _name,
|
|
class _NewNamedTupleType>
|
|
struct remove_single_field<_OldNamedTupleType, _name, _NewNamedTupleType, 0> {
|
|
using type = _NewNamedTupleType;
|
|
};
|
|
|
|
/// General case.
|
|
template <class _OldNamedTupleType, StringLiteral _name,
|
|
class _NewNamedTupleType, int _i>
|
|
struct remove_single_field {
|
|
using OldNamedTupleType = std::remove_cvref_t<_OldNamedTupleType>;
|
|
|
|
constexpr static int num_fields =
|
|
std::tuple_size_v<typename OldNamedTupleType::Fields>;
|
|
|
|
using FieldType = std::remove_cvref_t<typename std::tuple_element<
|
|
num_fields - _i, typename OldNamedTupleType::Fields>::type>;
|
|
|
|
using NewNamedTupleType =
|
|
std::conditional_t<_name == FieldType::name_, _NewNamedTupleType,
|
|
define_named_tuple_t<_NewNamedTupleType, FieldType>>;
|
|
|
|
using type = typename remove_single_field<OldNamedTupleType, _name,
|
|
NewNamedTupleType, _i - 1>::type;
|
|
};
|
|
|
|
/// Recursively removes all of the fields signified by _head and _tail from the
|
|
/// NamedTupleType.
|
|
template <class _NamedTupleType, StringLiteral _head, StringLiteral... _tail>
|
|
struct remove_fields;
|
|
|
|
/// Special case - only head is left.
|
|
template <class _NamedTupleType, StringLiteral _head>
|
|
struct remove_fields<_NamedTupleType, _head> {
|
|
using NamedTupleType = std::remove_cvref_t<_NamedTupleType>;
|
|
|
|
constexpr static int num_fields =
|
|
std::tuple_size_v<typename NamedTupleType::Fields>;
|
|
|
|
using type = typename remove_single_field<NamedTupleType, _head, NamedTuple<>,
|
|
num_fields>::type;
|
|
};
|
|
|
|
/// General case.
|
|
template <class _NamedTupleType, StringLiteral _head, StringLiteral... _tail>
|
|
struct remove_fields {
|
|
using NamedTupleType = std::remove_cvref_t<_NamedTupleType>;
|
|
|
|
constexpr static int num_fields =
|
|
std::tuple_size_v<typename NamedTupleType::Fields>;
|
|
|
|
using NewNamedTupleType =
|
|
typename remove_single_field<NamedTupleType, _head, NamedTuple<>,
|
|
num_fields>::type;
|
|
|
|
using type = typename remove_fields<NewNamedTupleType, _tail...>::type;
|
|
};
|
|
|
|
} // namespace internal
|
|
} // namespace rfl
|
|
|
|
#endif // RFL_REMOVEFIELDS_HPP_
|