68 lines
2.5 KiB
C
68 lines
2.5 KiB
C
|
// Copyright 2022 The Tint Authors.
|
||
|
|
//
|
||
|
|
// Licensed under the Apache License, Version 2.0 (the "License");
|
||
|
|
// you may not use this file except in compliance with the License.
|
||
|
|
// You may obtain a copy of the License at
|
||
|
|
//
|
||
|
|
// http://www.apache.org/licenses/LICENSE-2.0
|
||
|
|
//
|
||
|
|
// Unless required by applicable law or agreed to in writing, software
|
||
|
|
// distributed under the License is distributed on an "AS IS" BASIS,
|
||
|
|
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
|
||
|
|
// See the License for the specific language governing permissions and
|
||
|
|
// limitations under the License.
|
||
|
|
|
||
|
|
#ifndef SRC_TINT_REFLECTION_H_
|
||
|
|
#define SRC_TINT_REFLECTION_H_
|
||
|
|
|
||
|
|
#include "src/tint/traits.h"
|
||
|
|
#include "src/tint/utils/concat.h"
|
||
|
|
#include "src/tint/utils/foreach_macro.h"
|
||
|
|
|
||
|
|
namespace tint {
|
||
|
|
|
||
|
|
namespace detail {
|
||
|
|
|
||
|
|
/// Helper for detecting whether the type T contains a nested Reflection class.
|
||
|
|
template <typename T, typename ENABLE = void>
|
||
|
|
struct HasReflection : std::false_type {};
|
||
|
|
|
||
|
|
/// Specialization for types that have a nested Reflection class.
|
||
|
|
template <typename T>
|
||
|
|
struct HasReflection<T, std::void_t<typename T::Reflection>> : std::true_type {};
|
||
|
|
|
||
|
|
} // namespace detail
|
||
|
|
|
||
|
|
/// Is true if the class T has reflected its fields with TINT_REFLECT()
|
||
|
|
template <typename T>
|
||
|
|
static constexpr bool HasReflection = detail::HasReflection<T>::value;
|
||
|
|
|
||
|
|
/// Calls @p callback with each field of @p object
|
||
|
|
/// @param object the object
|
||
|
|
/// @param callback a function that is called for each field of @p object.
|
||
|
|
/// @tparam CB a function with the signature `void(FIELD)`
|
||
|
|
template <typename OBJECT, typename CB>
|
||
|
|
void ForeachField(OBJECT&& object, CB&& callback) {
|
||
|
|
using T = std::decay_t<OBJECT>;
|
||
|
|
static_assert(HasReflection<T>, "object type requires a tint::Reflect<> specialization");
|
||
|
|
T::Reflection::Fields(object, callback);
|
||
|
|
}
|
||
|
|
|
||
|
|
/// Macro used by TINT_FOREACH() in TINT_REFLECT() to call the callback function with each field in
|
||
|
|
/// the variadic.
|
||
|
|
#define TINT_REFLECT_CALLBACK_FIELD(field) callback(object.field);
|
||
|
|
|
||
|
|
// TINT_REFLECT(...) reflects each of the fields arguments so that the types can be used with
|
||
|
|
// tint::ForeachField().
|
||
|
|
#define TINT_REFLECT(...) \
|
||
|
|
struct Reflection { \
|
||
|
|
template <typename OBJECT, typename CB> \
|
||
|
|
static void Fields(OBJECT&& object, CB&& callback) { \
|
||
|
|
TINT_FOREACH(TINT_REFLECT_CALLBACK_FIELD, __VA_ARGS__) \
|
||
|
|
} \
|
||
|
|
}
|
||
|
|
|
||
|
|
} // namespace tint
|
||
|
|
|
||
|
|
#endif // SRC_TINT_REFLECTION_H_
|