Hi,
I think that in order to implement the resolution we simply have to
remove the check. Tested x86_64-linux.
Thanks,
Paolo.
//////////////////////
/cp
2014-09-01 Paolo Carlini <paolo.carl...@oracle.com>
DR 1405
PR c++/58102
* semantics.c (cxx_eval_outermost_constant_expr): Do not check
for mutable sub-objects.
/testsuite
2014-09-01 Paolo Carlini <paolo.carl...@oracle.com>
DR 1405
PR c++/58102
* g++.dg/cpp0x/constexpr-mutable2.C: New.
* g++.dg/cpp0x/constexpr-mutable1.C: Adjust.
Index: cp/semantics.c
===================================================================
--- cp/semantics.c (revision 214779)
+++ cp/semantics.c (working copy)
@@ -9858,18 +9858,6 @@ cxx_eval_outermost_constant_expr (tree t, bool all
verify_constant (r, allow_non_constant, &non_constant_p, &overflow_p);
- if (TREE_CODE (t) != CONSTRUCTOR
- && cp_has_mutable_p (TREE_TYPE (t)))
- {
- /* We allow a mutable type if the original expression was a
- CONSTRUCTOR so that we can do aggregate initialization of
- constexpr variables. */
- if (!allow_non_constant)
- error ("%qT cannot be the type of a complete constant expression "
- "because it has mutable sub-objects", TREE_TYPE (t));
- non_constant_p = true;
- }
-
/* Technically we should check this for all subexpressions, but that
runs into problems with our internal representation of pointer
subtraction and the 5.19 rules are still in flux. */
Index: testsuite/g++.dg/cpp0x/constexpr-mutable1.C
===================================================================
--- testsuite/g++.dg/cpp0x/constexpr-mutable1.C (revision 214785)
+++ testsuite/g++.dg/cpp0x/constexpr-mutable1.C (working copy)
@@ -7,6 +7,6 @@ struct A
};
constexpr A a = { 0, 1 };
-constexpr A b = a; // { dg-error "mutable" }
+constexpr A b = a;
constexpr int i = a.i;
constexpr int j = a.j; // { dg-error "mutable" }
Index: testsuite/g++.dg/cpp0x/constexpr-mutable2.C
===================================================================
--- testsuite/g++.dg/cpp0x/constexpr-mutable2.C (revision 0)
+++ testsuite/g++.dg/cpp0x/constexpr-mutable2.C (working copy)
@@ -0,0 +1,10 @@
+// DR 1405, PR c++/58102
+// { dg-do compile { target c++11 } }
+
+struct S {
+ mutable int n;
+ constexpr S() : n() {}
+};
+
+constexpr S s1 {};
+constexpr S s2 = {};
