re PR c++/56268 (C++11 ICE with boost multi-precision and boost variant during assignment)

	PR c++/56268
	* semantics.c (classtype_has_nothrow_assign_or_copy_p): Call
	maybe_instantiate_noexcept.

From-SVN: r195943

gcc/cp/ChangeLog

 2013-02-09  Jason Merrill  <jason@redhat.com>
 
+	PR c++/56268
+	* semantics.c (classtype_has_nothrow_assign_or_copy_p): Call
+	maybe_instantiate_noexcept.
+
 	PR c++/56247
 	* pt.c (eq_specializations): Set comparing_specializations.
 	* tree.c (cp_tree_equal): Check it.

gcc/cp/semantics.c

@@ -5413,6 +5413,7 @@ classtype_has_nothrow_assign_or_copy_p (tree type, bool assign_p)
       else if (copy_fn_p (fn) <= 0)
 	continue;
 
+      maybe_instantiate_noexcept (fn);
       if (!TYPE_NOTHROW_P (TREE_TYPE (fn)))
 	return false;
     }

gcc/testsuite/g++.dg/ext/has_nothrow_copy-8.C

+// PR c++/56268
+// { dg-options -std=c++11 }
+
+template <class T>
+struct A {
+  A(const A&) noexcept (T::value);
+};
+
+struct B {
+  static const bool value = true;
+};
+
+template <class T>
+struct C {
+  static const bool value = __has_nothrow_copy (T);
+};
+
+#define SA(X) static_assert((X),#X)
+SA(C<A<B>>::value);