140b4adcfe
Original-commit: flang-compiler/f18@e468f8cd54 Reviewed-on: https://github.com/flang-compiler/f18/pull/271 Tree-same-pre-rewrite: false
43 lines
1.3 KiB
C++
43 lines
1.3 KiB
C++
// Copyright (c) 2019, NVIDIA CORPORATION. All rights reserved.
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//
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// Licensed under the Apache License, Version 2.0 (the "License");
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// you may not use this file except in compliance with the License.
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// You may obtain a copy of the License at
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//
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// http://www.apache.org/licenses/LICENSE-2.0
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//
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// Unless required by applicable law or agreed to in writing, software
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// distributed under the License is distributed on an "AS IS" BASIS,
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// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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// See the License for the specific language governing permissions and
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// limitations under the License.
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// Utility: before overwriting a variable, capture its value and
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// ensure that it will be restored when the Restorer goes out of scope.
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//
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// int x{3};
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// {
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// auto save{common::ScopedSet(x, 4)};
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// // x is now 4
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// }
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// // x is back to 3
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#ifndef FORTRAN_COMMON_RESTORER_H_
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#define FORTRAN_COMMON_RESTORER_H_
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namespace Fortran::common {
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template<typename A> class Restorer {
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public:
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explicit Restorer(A &p) : p_{p}, original_{std::move(p)} {}
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~Restorer() { p_ = std::move(original_); }
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private:
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A &p_;
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A original_;
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};
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template<typename A> Restorer<A> ScopedSet(A &to, A &&from) {
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Restorer<A> result{to};
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to = std::move(from);
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return result;
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}
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}
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#endif // FORTRAN_COMMON_RESTORER_H_
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