* c.opt (-fdeduce-init-list): Off by default.

From-SVN: r180728

gcc/c-family/ChangeLog

 2011-10-31  Jason Merrill  <jason@redhat.com>
 
+	* c.opt (-fdeduce-init-list): Off by default.
+
 	PR c++/50920
 	* c-common.h (cxx_dialect): Add cxx11 and cxx03.
 	* c.opt: Add -std=c++11, -std=gnu++11, -std=gnu++03,

gcc/c-family/c.opt

@@ -752,8 +752,8 @@ C ObjC C++ ObjC++
 Emit debug annotations during preprocessing
 
 fdeduce-init-list
-C++ ObjC++ Var(flag_deduce_init_list) Init(1)
--fno-deduce-init-list	disable deduction of std::initializer_list for a template type parameter from a brace-enclosed initializer-list
+C++ ObjC++ Var(flag_deduce_init_list) Init(0)
+-fdeduce-init-list	enable deduction of std::initializer_list for a template type parameter from a brace-enclosed initializer-list
 
 fdefault-inline
 C++ ObjC++ Ignore

gcc/doc/invoke.texi

@@ -1907,9 +1907,9 @@ to @var{n}.  A limit is needed to detect endless recursion during
 constant expression evaluation.  The minimum specified by the standard
 is 512.
 
-@item -fno-deduce-init-list
-@opindex fno-deduce-init-list
-Disable deduction of a template type parameter as
+@item -fdeduce-init-list
+@opindex fdeduce-init-list
+Enable deduction of a template type parameter as
 std::initializer_list from a brace-enclosed initializer list, i.e.
 
 @smallexample
@@ -1924,9 +1924,10 @@ void f()
 @}
 @end smallexample
 
-This option is present because this deduction is an extension to the
-current specification in the C++0x working draft, and there was
-some concern about potential overload resolution problems.
+This deduction was implemented as a possible extension to the
+originally proposed semantics for the C++11 standard, but was not part
+of the final standard, so it is disabled by default.  This option is
+deprecated, and may be removed in a future version of G++.
 
 @item -ffriend-injection
 @opindex ffriend-injection

gcc/testsuite/g++.dg/cpp0x/initlist-deduce.C

@@ -2,7 +2,7 @@
 // supported by the working draft, but is necessary for perfect forwarding
 // of initializer-lists to things that can take a std::initializer_list.
 
-// { dg-options -std=c++0x }
+// { dg-options "-std=c++0x -fdeduce-init-list" }
 // { dg-do run }
 
 #include <initializer_list>