155 lines
5.4 KiB
Markdown
155 lines
5.4 KiB
Markdown
[variant.relops]
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# 22 General utilities library [[utilities]](./#utilities)
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## 22.6 Variants [[variant]](variant#relops)
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### 22.6.6 Relational operators [variant.relops]
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[ð](#lib:operator==,variant)
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`template<class... Types>
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constexpr bool operator==(const variant<Types...>& v, const variant<Types...>& w);
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`
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[1](#1)
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[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/utilities.tex#L6653)
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*Constraints*: *GET*<i>(v) == *GET*<i>(w) is a valid expression that is
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convertible to bool, for all i[.](#1.sentence-1)
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[2](#2)
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[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/utilities.tex#L6658)
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*Returns*: If v.index() != w.index(), false;
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otherwise if v.valueless_by_exception(), true;
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otherwise *GET*<i>(v) == *GET*<i>(w) with i being v.index()[.](#2.sentence-1)
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[ð](#lib:operator!=,variant)
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`template<class... Types>
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constexpr bool operator!=(const variant<Types...>& v, const variant<Types...>& w);
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`
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[3](#3)
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[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/utilities.tex#L6672)
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*Constraints*: *GET*<i>(v) != *GET*<i>(w) is a valid expression that is
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convertible to bool, for all i[.](#3.sentence-1)
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[4](#4)
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[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/utilities.tex#L6677)
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*Returns*: If v.index() != w.index(), true;
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otherwise if v.valueless_by_exception(), false;
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otherwise *GET*<i>(v) != *GET*<i>(w) with i being v.index()[.](#4.sentence-1)
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[ð](#lib:operator%3c,variant)
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`template<class... Types>
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constexpr bool operator<(const variant<Types...>& v, const variant<Types...>& w);
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`
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[5](#5)
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[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/utilities.tex#L6691)
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*Constraints*: *GET*<i>(v) < *GET*<i>(w) is a valid expression that is
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convertible to bool, for all i[.](#5.sentence-1)
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[6](#6)
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[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/utilities.tex#L6696)
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*Returns*: If w.valueless_by_exception(), false;
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otherwise if v.valueless_by_exception(), true;
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otherwise, if v.index() < w.index(), true;
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otherwise if v.index() > w.index(), false;
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otherwise *GET*<i>(v) < *GET*<i>(w) with i being v.index()[.](#6.sentence-1)
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[ð](#lib:operator%3e,variant)
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`template<class... Types>
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constexpr bool operator>(const variant<Types...>& v, const variant<Types...>& w);
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`
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[7](#7)
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[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/utilities.tex#L6712)
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*Constraints*: *GET*<i>(v) > *GET*<i>(w) is a valid expression that is
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convertible to bool, for all i[.](#7.sentence-1)
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[8](#8)
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[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/utilities.tex#L6717)
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*Returns*: If v.valueless_by_exception(), false;
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otherwise if w.valueless_by_exception(), true;
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otherwise, if v.index() > w.index(), true;
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otherwise if v.index() < w.index(), false;
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otherwise *GET*<i>(v) > *GET*<i>(w) with i being v.index()[.](#8.sentence-1)
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[ð](#lib:operator%3c=,variant)
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`template<class... Types>
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constexpr bool operator<=(const variant<Types...>& v, const variant<Types...>& w);
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`
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[9](#9)
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[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/utilities.tex#L6733)
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*Constraints*: *GET*<i>(v) <= *GET*<i>(w) is a valid expression that is
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convertible to bool, for all i[.](#9.sentence-1)
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[10](#10)
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[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/utilities.tex#L6738)
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*Returns*: If v.valueless_by_exception(), true;
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otherwise if w.valueless_by_exception(), false;
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otherwise, if v.index() < w.index(), true;
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otherwise if v.index() > w.index(), false;
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otherwise *GET*<i>(v) <= *GET*<i>(w) with i being v.index()[.](#10.sentence-1)
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[ð](#lib:operator%3e=,variant)
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`template<class... Types>
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constexpr bool operator>=(const variant<Types...>& v, const variant<Types...>& w);
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`
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[11](#11)
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[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/utilities.tex#L6754)
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*Constraints*: *GET*<i>(v) >= *GET*<i>(w) is a valid expression that is
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convertible to bool, for all i[.](#11.sentence-1)
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[12](#12)
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[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/utilities.tex#L6759)
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*Returns*: If w.valueless_by_exception(), true;
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otherwise if v.valueless_by_exception(), false;
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otherwise, if v.index() > w.index(), true;
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otherwise if v.index() < w.index(), false;
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otherwise *GET*<i>(v) >= *GET*<i>(w) with i being v.index()[.](#12.sentence-1)
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[ð](#lib:operator%3c=%3e,variant)
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`template<class... Types> requires ([three_way_comparable](cmp.concept#concept:three_way_comparable "17.12.4 Concept three_way_comparable [cmp.concept]")<Types> && ...)
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constexpr common_comparison_category_t<compare_three_way_result_t<Types>...>
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operator<=>(const variant<Types...>& v, const variant<Types...>& w);
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`
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[13](#13)
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[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/utilities.tex#L6776)
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*Effects*: Equivalent to:if (v.valueless_by_exception() && w.valueless_by_exception())return strong_ordering::equal;if (v.valueless_by_exception()) return strong_ordering::less;if (w.valueless_by_exception()) return strong_ordering::greater;if (auto c = v.index() <=> w.index(); c != 0) return c;return *GET*<i>(v) <=> *GET*<i>(w); with i being v.index()[.](#13.sentence-1)
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