Avoid ambiguity between C++2a std::erase_if and LFTS version

These calls should have been qualified to avoid ADL anyway, but in C++2a
it becomes essential to qualify the calls in experimental::erase because
std::erase_if is also declared and the calls become ambiguous.

	* include/experimental/forward_list (experimental::erase): Qualify
	call to erase_if.
	* include/experimental/list (experimental::erase): Likewise.
	* include/std/forward_list (std::erase): Likewise.
	* include/std/list (std::erase): Likewise.

From-SVN: r268356

libstdc++-v3/ChangeLog

 2019-01-29  Jonathan Wakely  <jwakely@redhat.com>
 
+	* include/experimental/forward_list (experimental::erase): Qualify
+	call to erase_if.
+	* include/experimental/list (experimental::erase): Likewise.
+	* include/std/forward_list (std::erase): Likewise.
+	* include/std/list (std::erase): Likewise.
+
 	* testsuite/20_util/reference_wrapper/result_type.cc: Disable for
 	C++2a.
 	* testsuite/20_util/reference_wrapper/typedefs-2.cc: Likewise.

libstdc++-v3/include/experimental/forward_list

@@ -54,7 +54,9 @@ inline namespace fundamentals_v2
     erase(forward_list<_Tp, _Alloc>& __cont, const _Up& __value)
     {
       using __elem_type = typename forward_list<_Tp, _Alloc>::value_type;
-      erase_if(__cont, [&](__elem_type& __elem) { return __elem == __value; });
+      std::experimental::erase_if(__cont, [&](__elem_type& __elem) {
+	  return __elem == __value;
+      });
     }
 
   namespace pmr {

libstdc++-v3/include/experimental/list

@@ -54,7 +54,9 @@ inline namespace fundamentals_v2
     erase(list<_Tp, _Alloc>& __cont, const _Up& __value)
     {
       using __elem_type = typename list<_Tp, _Alloc>::value_type;
-      erase_if(__cont, [&](__elem_type& __elem) { return __elem == __value; });
+      experimental::erase_if(__cont, [&](__elem_type& __elem) {
+	  return __elem == __value;
+      });
     }
 
 namespace pmr {

libstdc++-v3/include/std/forward_list

@@ -78,8 +78,9 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
     erase(forward_list<_Tp, _Alloc>& __cont, const _Up& __value)
     {
       using __elem_type = typename forward_list<_Tp, _Alloc>::value_type;
-      return erase_if(__cont,
-		      [&](__elem_type& __elem) { return __elem == __value; });
+      return std::erase_if(__cont, [&](__elem_type& __elem) {
+	  return __elem == __value;
+      });
     }
 _GLIBCXX_END_NAMESPACE_VERSION
 } // namespace std

libstdc++-v3/include/std/list

@@ -102,8 +102,9 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
     erase(list<_Tp, _Alloc>& __cont, const _Up& __value)
     {
       using __elem_type = typename list<_Tp, _Alloc>::value_type;
-      return erase_if(__cont,
-		      [&](__elem_type& __elem) { return __elem == __value; });
+      return std::erase_if(__cont, [&](__elem_type& __elem) {
+	  return __elem == __value;
+      });
     }
 _GLIBCXX_END_NAMESPACE_VERSION
 } // namespace std