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61 lines
2.1 KiB
C++
61 lines
2.1 KiB
C++
//===--- Consumption.h - Value consumption for SIL --------------*- C++ -*-===//
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//
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// This source file is part of the Swift.org open source project
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//
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// Copyright (c) 2014 - 2016 Apple Inc. and the Swift project authors
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// Licensed under Apache License v2.0 with Runtime Library Exception
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//
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// See http://swift.org/LICENSE.txt for license information
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// See http://swift.org/CONTRIBUTORS.txt for the list of Swift project authors
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//
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//===----------------------------------------------------------------------===//
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//
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// This file defines the CastConsumptionKind enum, which describes
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// under what circumstances an operation consumes a value.
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//
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//===----------------------------------------------------------------------===//
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#ifndef SWIFT_SIL_CONSUMPTION_H
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#define SWIFT_SIL_CONSUMPTION_H
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namespace swift {
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/// Is an operation a "take"? A take consumes the original value,
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/// leaving it uninitialized.
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enum IsTake_t : bool { IsNotTake, IsTake };
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/// Is an operation an "initialization"? An initialization simply
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/// fills in an uninitialized address with a value; a
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/// non-initialization also consumes the value already there.
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enum IsInitialization_t : bool { IsNotInitialization, IsInitialization };
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/// The behavior of a dynamic cast operation on the source value.
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enum class CastConsumptionKind : unsigned char {
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/// The source value is always taken, regardless of whether the cast
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/// succeeds. That is, if the cast fails, the source value is
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/// destroyed.
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TakeAlways,
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/// The source value is taken only on a successful cast; otherwise,
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/// it is left in place.
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TakeOnSuccess,
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/// The source value is always left in place, and the destination
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/// value is copied into on success.
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CopyOnSuccess,
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};
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/// Should the source value be destroyed if the cast fails?
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inline bool shouldDestroyOnFailure(CastConsumptionKind kind) {
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return (kind == CastConsumptionKind::TakeAlways);
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}
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/// Should the source value be taken if the cast succeeds?
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inline IsTake_t shouldTakeOnSuccess(CastConsumptionKind kind) {
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return IsTake_t(kind != CastConsumptionKind::CopyOnSuccess);
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}
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} // end namespace swift
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#endif
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