[committed] libstdc++: Fix std::any constraints [PR101034]

[Jonathan Wakely via Gcc-patches]

        PR libstdc++/101034
        * include/std/any (any(in_place_t<T>, initializer_list<U>, A&&...))
        (any::emplace<T>(initializer_list<U>, A&&...)): Fix constraint
        to use lvalue.
        * testsuite/20_util/any/cons/101034.cc: New test.

Tested powerpc64le-linux. Committed to trunk.


commit 14f26c75d255ef05b706a12d25b003da8a2f5b45
Author: Jonathan Wakely <jwak...@redhat.com>
Date:   Mon Jun 14 14:18:33 2021

    libstdc++: Fix std::any constraints [PR101034]
    
            PR libstdc++/101034
    
    libstdc++-v3/ChangeLog:
    
            * include/std/any (any(in_place_t<T>, initializer_list<U>, A&&...))
            (any::emplace<T>(initializer_list<U>, A&&...)): Fix constraint
            to use lvalue.
            * testsuite/20_util/any/cons/101034.cc: New test.

diff --git a/libstdc++-v3/include/std/any b/libstdc++-v3/include/std/any
index 21120a9146f..a6995b79c43 100644
--- a/libstdc++-v3/include/std/any
+++ b/libstdc++-v3/include/std/any
@@ -205,7 +205,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
     /// the contained object.
     template <typename _Tp, typename _Up, typename... _Args,
              typename _VTp = decay_t<_Tp>, typename _Mgr = _Manager<_VTp>,
-             __any_constructible_t<_VTp, initializer_list<_Up>,
+             __any_constructible_t<_VTp, initializer_list<_Up>&,
                                    _Args&&...> = false>
       explicit
       any(in_place_type_t<_Tp>, initializer_list<_Up> __il, _Args&&... __args)
@@ -269,7 +269,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
     /// Emplace with an object created from @p __il and @p __args as
     /// the contained object.
     template <typename _Tp, typename _Up, typename... _Args>
-      __emplace_t<decay_t<_Tp>, initializer_list<_Up>, _Args&&...>
+      __emplace_t<decay_t<_Tp>, initializer_list<_Up>&, _Args&&...>
       emplace(initializer_list<_Up> __il, _Args&&... __args)
       {
        using _VTp = decay_t<_Tp>;
diff --git a/libstdc++-v3/testsuite/20_util/any/cons/101034.cc 
b/libstdc++-v3/testsuite/20_util/any/cons/101034.cc
new file mode 100644
index 00000000000..55f550a839e
--- /dev/null
+++ b/libstdc++-v3/testsuite/20_util/any/cons/101034.cc
@@ -0,0 +1,11 @@
+// { dg-do compile { target c++17 } }
+// PR libstdc++/101034 - wrong constraint in std::any's constructor
+
+#include <any>
+
+struct S {
+  S(std::initializer_list<int>&, int) {}
+};
+
+std::any a(std::in_place_type<S>, {0}, 0);
+S& s = a.emplace<S>({0}, 0);