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Jon Meow
fd89bcb4aa
Sorry about the big change, this is hard to split. ParenContents is used by both, templated, and expects the same pointer type. While I could duplicate ParenContents with some ExpressionParenContents or PatternParenContents, that seems a little kludgy versus a single large change handling both. The worst of it is that Expression is already pretty sweeping, Pattern is really just incrementally adding. That said, I believe this includes a couple fixes I found with incorrect use of dyn_cast in typecheck.cpp (checked nullptr at the wrong step in 2 code locations). There's also a missing `*` in member.cpp this caught. I adjust passing of expressions for Return due to nullness (I felt adding another constructor was the best solution). I add a `.Release()` to BisonWrap due to things like `$3.first` needing some way to work through BIsonWrap. I felt this was better than `operator->`, but feel free to comment if you prefer the other path (`.Release()` conveniently lets me do pair unwrapping, so it felt a better solution). I do add a TODO to think about better Ptr-to-Ptr cast<> support too, though, as that doesn't work cleanly with LLVM's infra. But so far it seems to only come up in one spot, so I'm not prioritizing it.
45 lines
1.2 KiB
C++
45 lines
1.2 KiB
C++
// Part of the Carbon Language project, under the Apache License v2.0 with LLVM
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// Exceptions. See /LICENSE for license information.
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// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
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#ifndef EXECUTABLE_SEMANTICS_SYNTAX_BISON_WRAP_H_
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#define EXECUTABLE_SEMANTICS_SYNTAX_BISON_WRAP_H_
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#include <optional>
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#include "common/check.h"
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namespace Carbon {
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// Bison requires that types be default initializable for use with its variant
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// semantics. This wraps arbitrary types to support a default constructor, while
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// still requiring they be properly initialized.
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template <typename T>
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class BisonWrap {
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public:
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// Assigning a value initializes the wrapper.
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BisonWrap& operator=(T&& rhs) {
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val = std::move(rhs);
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return *this;
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}
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// Support transparent conversion to the wrapped type.
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operator T() { return Release(); }
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// Deliberately releases the contained value. Errors if not initialized.
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// Called directly in parser.ypp when releasing pairs.
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auto Release() -> T {
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CHECK(val.has_value());
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T ret = std::move(*val);
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val.reset();
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return ret;
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}
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private:
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std::optional<T> val;
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};
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} // namespace Carbon
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#endif // EXECUTABLE_SEMANTICS_SYNTAX_BISON_WRAP_H_
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