libstdc++: Improve Doxygen comments in <tuple>
libstdc++-v3/ChangeLog:
* include/std/tuple: Add better Doxygen comments.
diff --git a/libstdc++-v3/include/std/tuple b/libstdc++-v3/include/std/tuple
index 26e2484..0ac592d 100644
--- a/libstdc++-v3/include/std/tuple
+++ b/libstdc++-v3/include/std/tuple
@@ -1980,6 +1980,7 @@
#endif // three_way_comparison
// NB: DR 705.
+ /// Create a tuple containing copies of the arguments
template<typename... _Elements>
constexpr tuple<typename __decay_and_strip<_Elements>::__type...>
make_tuple(_Elements&&... __args)
@@ -1991,7 +1992,7 @@
// _GLIBCXX_RESOLVE_LIB_DEFECTS
// 2275. Why is forward_as_tuple not constexpr?
- /// std::forward_as_tuple
+ /// Create a tuple of lvalue or rvalue references to the arguments
template<typename... _Elements>
constexpr tuple<_Elements&&...>
forward_as_tuple(_Elements&&... __args) noexcept
@@ -2018,7 +2019,7 @@
constexpr const _Tp&&
get(const array<_Tp, _Nm>&&) noexcept;
-
+ /// @cond undocumented
template<size_t, typename, typename, size_t>
struct __make_tuple_impl;
@@ -2130,8 +2131,9 @@
template<typename... _Tps>
struct __is_tuple_like_impl<tuple<_Tps...>> : true_type
{ };
+ /// @endcond
- /// tuple_cat
+ /// Create a `tuple` containing all elements from multiple tuple-like objects
template<typename... _Tpls, typename = typename
enable_if<__and_<__is_tuple_like<_Tpls>...>::value>::type>
constexpr auto
@@ -2146,13 +2148,13 @@
// _GLIBCXX_RESOLVE_LIB_DEFECTS
// 2301. Why is tie not constexpr?
- /// tie
+ /// Return a tuple of lvalue references bound to the arguments
template<typename... _Elements>
constexpr tuple<_Elements&...>
tie(_Elements&... __args) noexcept
{ return tuple<_Elements&...>(__args...); }
- /// swap
+ /// Exchange the values of two tuples
template<typename... _Elements>
_GLIBCXX20_CONSTEXPR
inline
@@ -2177,6 +2179,7 @@
#endif // C++23
#if __cplusplus > 201402L || !defined(__STRICT_ANSI__) // c++1z or gnu++11
+ /// Exchange the values of two const tuples (if const elements can be swapped)
template<typename... _Elements>
_GLIBCXX20_CONSTEXPR
typename enable_if<!__and_<__is_swappable<_Elements>...>::value>::type
@@ -2197,6 +2200,21 @@
// _GLIBCXX_RESOLVE_LIB_DEFECTS
// 2773. Making std::ignore constexpr
+ /** Used with `std::tie` to ignore an element of a tuple
+ *
+ * When using `std::tie` to assign the elements of a tuple to variables,
+ * unwanted elements can be ignored by using `std::ignore`. For example:
+ *
+ * ```
+ * int x, y;
+ * std::tie(x, std::ignore, y) = std::make_tuple(1, 2, 3);
+ * ```
+ *
+ * This assignment will perform `x=1; std::ignore=2; y=3;` which results
+ * in the second element being ignored.
+ *
+ * @since C++11
+ */
_GLIBCXX17_INLINE constexpr _Swallow_assign ignore{};
/// Partial specialization for tuples
