mirror of
https://github.com/carbon-language/carbon-lang.git
synced 2026-09-24 22:00:12 +01:00
Richard SmithandJon Ross-Perkins
c172487395
First step towards permitting declarations within namespaces. Supports only functions within namespaces for now, with no way to call those functions except from within other such functions. Unqualified lookups within a function in a namespace look in that namespace first. Co-authored-by: Jon Ross-Perkins <jperkins@google.com>
49 lines
1.3 KiB
C++
49 lines
1.3 KiB
C++
// Part of the Carbon Language project, under the Apache License v2.0 with LLVM
|
|
// Exceptions. See /LICENSE for license information.
|
|
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
|
|
|
|
#ifndef CARBON_EXPLORER_SYNTAX_BISON_WRAP_H_
|
|
#define CARBON_EXPLORER_SYNTAX_BISON_WRAP_H_
|
|
|
|
#include <optional>
|
|
|
|
#include "common/check.h"
|
|
|
|
namespace Carbon {
|
|
|
|
// Bison requires that types be default initializable for use with its variant
|
|
// semantics. This wraps arbitrary types to support a default constructor, while
|
|
// still requiring they be properly initialized.
|
|
template <typename T>
|
|
class BisonWrap {
|
|
public:
|
|
// Assigning a value initializes the wrapper.
|
|
auto operator=(T&& rhs) -> BisonWrap& {
|
|
val_ = std::move(rhs);
|
|
return *this;
|
|
}
|
|
|
|
// Support transparent conversion to the wrapped type.
|
|
// NOLINTNEXTLINE(google-explicit-constructor)
|
|
operator T() { return Release(); }
|
|
|
|
// Access the contained object, which must already have been set.
|
|
auto Unwrap() & -> T& { return *val_; }
|
|
|
|
// Deliberately releases the contained value. Errors if not initialized.
|
|
// Called directly in parser.ypp when releasing pairs.
|
|
auto Release() -> T {
|
|
CARBON_CHECK(val_.has_value());
|
|
T ret = std::move(*val_);
|
|
val_.reset();
|
|
return ret;
|
|
}
|
|
|
|
private:
|
|
std::optional<T> val_;
|
|
};
|
|
|
|
} // namespace Carbon
|
|
|
|
#endif // CARBON_EXPLORER_SYNTAX_BISON_WRAP_H_
|