You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
260 lines
9.1 KiB
260 lines
9.1 KiB
/*
|
|
* Copyright 2014 Google Inc. All rights reserved.
|
|
*
|
|
* 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 FRUIT_META_EVAL_H
|
|
#define FRUIT_META_EVAL_H
|
|
|
|
#include <fruit/impl/meta/basics.h>
|
|
#include <fruit/impl/meta/errors.h>
|
|
#include <fruit/impl/meta/logical_operations.h>
|
|
|
|
#include <functional>
|
|
|
|
namespace fruit {
|
|
namespace impl {
|
|
namespace meta {
|
|
|
|
template <typename MetaExpr>
|
|
struct DoEval;
|
|
|
|
// General case, meta-constant.
|
|
template <typename MetaExpr>
|
|
struct DoEval {
|
|
#if FRUIT_TRACE_INSTANTIATIONS
|
|
constexpr static bool static_warning() __attribute__((deprecated("static_warning"))) {
|
|
return true;
|
|
}
|
|
static_assert(static_warning(), "");
|
|
#endif
|
|
using type = MetaExpr;
|
|
};
|
|
|
|
template <typename Type>
|
|
struct SimpleIsError {
|
|
static constexpr bool value = false;
|
|
};
|
|
template <typename ErrorTag, typename... ErrorArgs>
|
|
struct SimpleIsError<Error<ErrorTag, ErrorArgs...>> {
|
|
static constexpr bool value = true;
|
|
};
|
|
|
|
#if FRUIT_EXTRA_DEBUG
|
|
|
|
// For debugging, we use a separate DoEvalFun so that we get longer (and more informative)
|
|
// instantiation traces.
|
|
|
|
template <typename MetaFun, typename... Params>
|
|
struct DoEvalFun {
|
|
using type =
|
|
typename DoEval<typename std::conditional<StaticOr<SimpleIsError<Params>::value...>::value, ExtractFirstError,
|
|
MetaFun>::type::template apply<Params...>::type>::type;
|
|
};
|
|
|
|
template <typename MetaFun, typename... MetaExprs>
|
|
struct DoEval<MetaFun(MetaExprs...)> {
|
|
#if FRUIT_TRACE_INSTANTIATIONS
|
|
constexpr static bool static_warning() __attribute__((deprecated("static_warning"))) {
|
|
return true;
|
|
}
|
|
static_assert(static_warning(), "");
|
|
#endif
|
|
using type = typename DoEvalFun<MetaFun, typename DoEval<MetaExprs>::type...>::type;
|
|
};
|
|
|
|
// Similar to the previous specialization, but this will be selected when the function signature
|
|
// became a function pointer (this happens when a signature parameter is itself a signature).
|
|
template <typename MetaFun, typename... MetaExprs>
|
|
struct DoEval<MetaFun (*)(MetaExprs...)> {
|
|
#if FRUIT_TRACE_INSTANTIATIONS
|
|
constexpr static bool static_warning() __attribute__((deprecated("static_warning"))) {
|
|
return true;
|
|
}
|
|
static_assert(static_warning(), "");
|
|
#endif
|
|
using type = typename DoEvalFun<MetaFun, typename DoEval<MetaExprs>::type...>::type;
|
|
};
|
|
|
|
#else // FRUIT_EXTRA_DEBUG
|
|
|
|
template <typename MetaFun, typename... MetaExprs>
|
|
struct DoEval<MetaFun(MetaExprs...)> {
|
|
#if FRUIT_TRACE_INSTANTIATIONS
|
|
constexpr static bool static_warning() __attribute__((deprecated("static_warning"))) {
|
|
return true;
|
|
}
|
|
static_assert(static_warning(), "");
|
|
#endif
|
|
using type = typename DoEval<typename std::conditional<
|
|
StaticOr<SimpleIsError<typename DoEval<MetaExprs>::type>::value...>::value, ExtractFirstError,
|
|
MetaFun>::type::template apply<typename DoEval<MetaExprs>::type...>::type>::type;
|
|
};
|
|
|
|
// Similar to the previous specialization, but this will be selected when the function signature
|
|
// became a function pointer (this happens when a signature parameter is itself a signature).
|
|
template <typename MetaFun, typename... MetaExprs>
|
|
struct DoEval<MetaFun (*)(MetaExprs...)> {
|
|
#if FRUIT_TRACE_INSTANTIATIONS
|
|
constexpr static bool static_warning() __attribute__((deprecated("static_warning"))) {
|
|
return true;
|
|
}
|
|
static_assert(static_warning(), "");
|
|
#endif
|
|
using type = typename DoEval<typename std::conditional<
|
|
StaticOr<SimpleIsError<typename DoEval<MetaExprs>::type>::value...>::value, ExtractFirstError,
|
|
MetaFun>::type::template apply<typename DoEval<MetaExprs>::type...>::type>::type;
|
|
};
|
|
|
|
#endif // FRUIT_EXTRA_DEBUG
|
|
|
|
template <typename ExprResult, typename ErrorTag, typename Handler>
|
|
struct EvalCatch {
|
|
using type = ExprResult;
|
|
};
|
|
|
|
template <typename CaughtErrorTag, typename... ErrorArgs, typename Handler>
|
|
struct EvalCatch<Error<CaughtErrorTag, ErrorArgs...>, CaughtErrorTag, Handler> {
|
|
using type =
|
|
typename DoEval<typename DoEval<Handler>::type::template apply<Error<CaughtErrorTag, ErrorArgs...>>::type>::type;
|
|
};
|
|
|
|
template <typename ExprResult, typename Handler>
|
|
struct EvalCatchAll {
|
|
using type = ExprResult;
|
|
};
|
|
|
|
template <typename CaughtErrorTag, typename... ErrorArgs, typename Handler>
|
|
struct EvalCatchAll<Error<CaughtErrorTag, ErrorArgs...>, Handler> {
|
|
using type =
|
|
typename DoEval<typename DoEval<Handler>::type::template apply<Error<CaughtErrorTag, ErrorArgs...>>::type>::type;
|
|
};
|
|
|
|
template <typename Expr, typename ErrorTag, typename Handler>
|
|
struct DoEval<Catch(Expr, ErrorTag, Handler)> {
|
|
using type = typename EvalCatch<typename DoEval<Expr>::type, typename DoEval<ErrorTag>::type, Handler>::type;
|
|
};
|
|
|
|
template <typename Expr, typename ErrorTag, typename Handler>
|
|
struct DoEval<Catch (*)(Expr, ErrorTag, Handler)> {
|
|
using type = typename EvalCatch<typename DoEval<Expr>::type, typename DoEval<ErrorTag>::type, Handler>::type;
|
|
};
|
|
|
|
template <typename Expr, typename Handler>
|
|
struct DoEval<CatchAll(Expr, Handler)> {
|
|
using type = typename EvalCatchAll<typename DoEval<Expr>::type, Handler>::type;
|
|
};
|
|
|
|
template <typename Expr, typename Handler>
|
|
struct DoEval<CatchAll (*)(Expr, Handler)> {
|
|
using type = typename EvalCatchAll<typename DoEval<Expr>::type, Handler>::type;
|
|
};
|
|
|
|
template <typename MetaBool, typename ThenMetaExpr, typename ElseMetaExpr>
|
|
struct EvalIf;
|
|
|
|
template <typename ErrorTag, typename... ErrorArgs, typename ThenMetaExpr, typename ElseMetaExpr>
|
|
struct EvalIf<Error<ErrorTag, ErrorArgs...>, ThenMetaExpr, ElseMetaExpr> {
|
|
using type = Error<ErrorTag, ErrorArgs...>;
|
|
};
|
|
|
|
template <typename ThenMetaExpr, typename ElseMetaExpr>
|
|
struct EvalIf<Bool<true>, ThenMetaExpr, ElseMetaExpr> {
|
|
#if FRUIT_TRACE_INSTANTIATIONS
|
|
constexpr static bool static_warning() __attribute__((deprecated("static_warning"))) {
|
|
return true;
|
|
}
|
|
static_assert(static_warning(), "");
|
|
#endif
|
|
using type = typename DoEval<ThenMetaExpr>::type;
|
|
};
|
|
|
|
template <typename ThenMetaExpr, typename ElseMetaExpr>
|
|
struct EvalIf<Bool<false>, ThenMetaExpr, ElseMetaExpr> {
|
|
#if FRUIT_TRACE_INSTANTIATIONS
|
|
constexpr static bool static_warning() __attribute__((deprecated("static_warning"))) {
|
|
return true;
|
|
}
|
|
static_assert(static_warning(), "");
|
|
#endif
|
|
using type = typename DoEval<ElseMetaExpr>::type;
|
|
};
|
|
|
|
template <typename CondMetaExpr, typename ThenMetaExpr, typename ElseMetaExpr>
|
|
struct DoEval<If(CondMetaExpr, ThenMetaExpr, ElseMetaExpr)> {
|
|
#if FRUIT_TRACE_INSTANTIATIONS
|
|
constexpr static bool static_warning() __attribute__((deprecated("static_warning"))) {
|
|
return true;
|
|
}
|
|
static_assert(static_warning(), "");
|
|
#endif
|
|
using type = typename EvalIf<typename DoEval<CondMetaExpr>::type, ThenMetaExpr, ElseMetaExpr>::type;
|
|
};
|
|
|
|
// Similar to the previous specialization, but this will be selected when the function signature
|
|
// became a function pointer (this happens when a signature parameter is itself a signature).
|
|
template <typename CondMetaExpr, typename ThenMetaExpr, typename ElseMetaExpr>
|
|
struct DoEval<If (*)(CondMetaExpr, ThenMetaExpr, ElseMetaExpr)> {
|
|
#if FRUIT_TRACE_INSTANTIATIONS
|
|
constexpr static bool static_warning() __attribute__((deprecated("static_warning"))) {
|
|
return true;
|
|
}
|
|
static_assert(static_warning(), "");
|
|
#endif
|
|
using type = typename EvalIf<typename DoEval<CondMetaExpr>::type, ThenMetaExpr, ElseMetaExpr>::type;
|
|
};
|
|
|
|
template <typename T, typename ElseMetaExpr>
|
|
struct EvalPropagateError {
|
|
using type = typename DoEval<ElseMetaExpr>::type;
|
|
};
|
|
|
|
template <typename ErrorTag, typename... ErrorArgs, typename ElseMetaExpr>
|
|
struct EvalPropagateError<Error<ErrorTag, ErrorArgs...>, ElseMetaExpr> {
|
|
using type = Error<ErrorTag, ErrorArgs...>;
|
|
};
|
|
|
|
template <typename MaybeErrorMetaExpr, typename ElseMetaExpr>
|
|
struct DoEval<PropagateError(MaybeErrorMetaExpr, ElseMetaExpr)> {
|
|
#if FRUIT_TRACE_INSTANTIATIONS
|
|
constexpr static bool static_warning() __attribute__((deprecated("static_warning"))) {
|
|
return true;
|
|
}
|
|
static_assert(static_warning(), "");
|
|
#endif
|
|
using type = typename EvalPropagateError<typename DoEval<MaybeErrorMetaExpr>::type, ElseMetaExpr>::type;
|
|
};
|
|
|
|
// Similar to the previous specialization, but this will be selected when the function signature
|
|
// became a function pointer (this happens when a signature parameter is itself a signature).
|
|
template <typename MaybeErrorMetaExpr, typename ElseMetaExpr>
|
|
struct DoEval<PropagateError (*)(MaybeErrorMetaExpr, ElseMetaExpr)> {
|
|
#if FRUIT_TRACE_INSTANTIATIONS
|
|
constexpr static bool static_warning() __attribute__((deprecated("static_warning"))) {
|
|
return true;
|
|
}
|
|
static_assert(static_warning(), "");
|
|
#endif
|
|
using type = typename EvalPropagateError<typename DoEval<MaybeErrorMetaExpr>::type, ElseMetaExpr>::type;
|
|
};
|
|
|
|
template <typename MetaExpr>
|
|
using Eval = typename DoEval<MetaExpr>::type;
|
|
|
|
} // namespace meta
|
|
} // namespace impl
|
|
} // namespace fruit
|
|
|
|
#endif // FRUIT_META_EVAL_H
|