From Jason Turner

[tuple.cnstr]

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tmp/tmpdf_37zkl/{from.md → to.md} RENAMED
@@ -110,11 +110,11 @@ template<class... UTypes> constexpr explicit(see below) tuple(tuple<UTypes...>&
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  template<class... UTypes> constexpr explicit(see below) tuple(const tuple<UTypes...>& u);
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  template<class... UTypes> constexpr explicit(see below) tuple(tuple<UTypes...>&& u);
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  template<class... UTypes> constexpr explicit(see below) tuple(const tuple<UTypes...>&& u);
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  ```
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- Let `I` be the pack `0, 1, ..., (sizeof...(Types) - 1)`. Let
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  *`FWD`*`(u)` be `static_cast<decltype(u)>(u)`.
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  *Constraints:*
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  - `sizeof...(Types)` equals `sizeof...(UTypes)`, and
@@ -181,21 +181,21 @@ is `true`.
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  ``` cpp
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  template<tuple-like UTuple>
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  constexpr explicit(see below) tuple(UTuple&& u);
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  ```
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- Let `I` be the pack `0, 1, …, (sizeof...(Types) - 1)`.
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  *Constraints:*
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  - `different-from<UTuple, tuple>` [[range.utility.helpers]] is `true`,
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  - `remove_cvref_t<UTuple>` is not a specialization of
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  `ranges::subrange`,
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  - `sizeof...(Types)` equals `tuple_size_v<remove_cvref_t<UTuple>>`,
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  - `(is_constructible_v<Types, decltype(get<I>(std::forward<UTuple>(u)))> && ...)`
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  is `true`, and
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- - either `sizeof...(Types)` is not `1`, or (when `Types...` expands to
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  `T`) `is_convertible_v<UTuple, T>` and `is_constructible_v<T, UTuple>`
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  are both `false`.
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  *Effects:* For all i, initializes the iᵗʰ element of `*this` with
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  `get<`i`>(std::forward<UTuple>(u))`.
@@ -204,10 +204,19 @@ Let `I` be the pack `0, 1, …, (sizeof...(Types) - 1)`.
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  ``` cpp
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  !(is_convertible_v<decltype(get<I>(std::forward<UTuple>(u))), Types> && ...)
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  ```
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  ``` cpp
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  template<class Alloc>
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  constexpr explicit(see below)
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  tuple(allocator_arg_t, const Alloc& a);
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  template<class Alloc>
 
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  template<class... UTypes> constexpr explicit(see below) tuple(const tuple<UTypes...>& u);
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  template<class... UTypes> constexpr explicit(see below) tuple(tuple<UTypes...>&& u);
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  template<class... UTypes> constexpr explicit(see below) tuple(const tuple<UTypes...>&& u);
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  ```
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+ Let `I` be the pack `0, 1, `…`, (sizeof...(Types) - 1)`. Let
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  *`FWD`*`(u)` be `static_cast<decltype(u)>(u)`.
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  *Constraints:*
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  - `sizeof...(Types)` equals `sizeof...(UTypes)`, and
 
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  ``` cpp
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  template<tuple-like UTuple>
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  constexpr explicit(see below) tuple(UTuple&& u);
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  ```
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+ Let `I` be the pack `0, 1, `…`, (sizeof...(Types) - 1)`.
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  *Constraints:*
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  - `different-from<UTuple, tuple>` [[range.utility.helpers]] is `true`,
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  - `remove_cvref_t<UTuple>` is not a specialization of
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  `ranges::subrange`,
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  - `sizeof...(Types)` equals `tuple_size_v<remove_cvref_t<UTuple>>`,
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  - `(is_constructible_v<Types, decltype(get<I>(std::forward<UTuple>(u)))> && ...)`
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  is `true`, and
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+ - either `sizeof...(Types)` is not 1, or (when `Types...` expands to
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  `T`) `is_convertible_v<UTuple, T>` and `is_constructible_v<T, UTuple>`
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  are both `false`.
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  *Effects:* For all i, initializes the iᵗʰ element of `*this` with
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  `get<`i`>(std::forward<UTuple>(u))`.
 
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  ``` cpp
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  !(is_convertible_v<decltype(get<I>(std::forward<UTuple>(u))), Types> && ...)
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  ```
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+ The constructor is defined as deleted if
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+
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+ ``` cpp
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+ (reference_constructs_from_temporary_v<Types, decltype(get<I>(std::forward<UTuple>(u)))>
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+ || ...)
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+ ```
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+
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+ is `true`.
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+
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  ``` cpp
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  template<class Alloc>
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  constexpr explicit(see below)
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  tuple(allocator_arg_t, const Alloc& a);
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  template<class Alloc>