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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-05-04 17:44:55 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-05-04 17:44:55 +0000 |
commit | 5068d34c08f951a7ea6257d305a1627b09a95817 (patch) | |
tree | 08213e2be853396a3b07ce15dbe222644dcd9a89 /src/mapbox/optional.hpp | |
parent | Initial commit. (diff) | |
download | lnav-upstream.tar.xz lnav-upstream.zip |
Adding upstream version 0.11.1.upstream/0.11.1upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to '')
-rw-r--r-- | src/mapbox/optional.hpp | 74 |
1 files changed, 74 insertions, 0 deletions
diff --git a/src/mapbox/optional.hpp b/src/mapbox/optional.hpp new file mode 100644 index 0000000..d84705c --- /dev/null +++ b/src/mapbox/optional.hpp @@ -0,0 +1,74 @@ +#ifndef MAPBOX_UTIL_OPTIONAL_HPP +#define MAPBOX_UTIL_OPTIONAL_HPP + +#pragma message("This implementation of optional is deprecated. See https://github.com/mapbox/variant/issues/64.") + +#include <type_traits> +#include <utility> + +#include <mapbox/variant.hpp> + +namespace mapbox { +namespace util { + +template <typename T> +class optional +{ + static_assert(!std::is_reference<T>::value, "optional doesn't support references"); + + struct none_type + { + }; + + variant<none_type, T> variant_; + +public: + optional() = default; + + optional(optional const& rhs) + { + if (this != &rhs) + { // protect against invalid self-assignment + variant_ = rhs.variant_; + } + } + + optional(T const& v) { variant_ = v; } + + explicit operator bool() const noexcept { return variant_.template is<T>(); } + + T const& get() const { return variant_.template get<T>(); } + T& get() { return variant_.template get<T>(); } + + T const& operator*() const { return this->get(); } + T operator*() { return this->get(); } + + optional& operator=(T const& v) + { + variant_ = v; + return *this; + } + + optional& operator=(optional const& rhs) + { + if (this != &rhs) + { + variant_ = rhs.variant_; + } + return *this; + } + + template <typename... Args> + void emplace(Args&&... args) + { + variant_ = T{std::forward<Args>(args)...}; + } + + void reset() { variant_ = none_type{}; } + +}; // class optional + +} // namespace util +} // namespace mapbox + +#endif // MAPBOX_UTIL_OPTIONAL_HPP |