From b65bdd27fd96afa3074308de18d6a54c67ba6aef Mon Sep 17 00:00:00 2001
From: Jonathan Wakely <jwakely@redhat.com>
Date: Tue, 10 Dec 2019 16:15:55 +0000
Subject: [PATCH] libstdc++: Reduce header dependencies in <span>

	* include/std/span: Do not include <tuple> and <utility>.
	(tuple_size, tuple_element): Declare.

From-SVN: r279171
---
 libstdc++-v3/ChangeLog        | 3 +++
 libstdc++-v3/include/std/span | 5 +++--
 2 files changed, 6 insertions(+), 2 deletions(-)

diff --git a/libstdc++-v3/ChangeLog b/libstdc++-v3/ChangeLog
index f25e040..38c8441 100644
--- a/libstdc++-v3/ChangeLog
+++ b/libstdc++-v3/ChangeLog
@@ -1,5 +1,8 @@
 2019-12-10  Jonathan Wakely  <jwakely@redhat.com>
 
+	* include/std/span: Do not include <tuple> and <utility>.
+	(tuple_size, tuple_element): Declare.
+
 	* include/bits/iterator_concepts.h (indirect_result_t): Do not apply
 	iter_reference_t to parameter pack.
 	* testsuite/24_iterators/indirect_callable/projected.cc: New test.
diff --git a/libstdc++-v3/include/std/span b/libstdc++-v3/include/std/span
index f215dec..ecce0b3 100644
--- a/libstdc++-v3/include/std/span
+++ b/libstdc++-v3/include/std/span
@@ -39,8 +39,6 @@
 #if __cplusplus > 201703L
 
 #include <type_traits>
-#include <tuple>
-#include <utility>
 #include <array>
 #include <bits/stl_iterator.h>
 #include <bits/range_access.h>
@@ -451,6 +449,9 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
       return __sp[_Index];
     }
 
+  template<typename _Tp> struct tuple_size;
+  template<size_t __i, typename _Tp> struct tuple_element;
+
   template<typename _Type, size_t _Extent>
     struct tuple_size<span<_Type, _Extent>>
     : public integral_constant<size_t, _Extent>
-- 
2.7.4