re PR c++/64455 (A constexpr variable template can't be used with enable_if)

PR c++/64455
	* pt.c (type_dependent_expression_p): Handle variable templates.
	* constexpr.c (potential_constant_expression_1): Use it.

From-SVN: r219268
This commit is contained in:
Jason Merrill 2015-01-06 15:44:51 -05:00 committed by Jason Merrill
parent b433d944ab
commit c6a38536f2
4 changed files with 38 additions and 1 deletions

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@ -1,5 +1,9 @@
2015-01-06 Jason Merrill <jason@redhat.com>
PR c++/64455
* pt.c (type_dependent_expression_p): Handle variable templates.
* constexpr.c (potential_constant_expression_1): Use it.
PR c++/64487
* semantics.c (finish_offsetof): Handle templates here.
* parser.c (cp_parser_builtin_offsetof): Not here.

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@ -3882,7 +3882,7 @@ potential_constant_expression_1 (tree t, bool want_rval, bool strict,
|| !CP_TYPE_CONST_NON_VOLATILE_P (TREE_TYPE (t))
|| !DECL_INITIALIZED_BY_CONSTANT_EXPRESSION_P (t))
&& !var_in_constexpr_fn (t)
&& !dependent_type_p (TREE_TYPE (t)))
&& !type_dependent_expression_p (t))
{
if (flags & tf_error)
non_const_var_error (t);

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@ -21369,6 +21369,14 @@ type_dependent_expression_p (tree expression)
&& DECL_INITIAL (expression))
return true;
/* A variable template specialization is type-dependent if it has any
dependent template arguments. */
if (VAR_P (expression)
&& DECL_LANG_SPECIFIC (expression)
&& DECL_TEMPLATE_INFO (expression)
&& variable_template_p (DECL_TI_TEMPLATE (expression)))
return any_dependent_template_arguments_p (DECL_TI_ARGS (expression));
if (TREE_TYPE (expression) == unknown_type_node)
{
if (TREE_CODE (expression) == ADDR_EXPR)

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@ -0,0 +1,25 @@
// PR c++/64455
// { dg-do compile { target c++14 } }
template<typename Type>
constexpr bool IsType = true;
template <bool b, class T> struct Test
{
};
template <class T>
struct Test<true, T>
{
typedef T type;
};
template<class T>
struct X {
typedef typename Test<IsType<T>,T>::type type;
};
int main()
{
X<int>::type t;
}