[C++ PATCH] (regression) Set TREE_CONSTANT for STATIC_EXPR and CAST_EXPR

[Giovanni Bajo]

Gabriel Dos Reis <gdr@integrable-solutions.net> wrote:

>> Au contraire!
>>
>> They can be checked whenever we want to check them, and early is good.
>
> In processing
>
>   template<class Q>
>    struct X {
>       typedef typename Q::T T;
>       static const T a = Q::a;
>    };
>
> there is no way of knowing whether Q::a is a valid initializer.

But Q::a is dependent. Mark is saying that we should try and check any
non-dependent expression at parsing time, and postpone semantic checks of
dependent expressions only at instantiation point. That is, enforcing most
of the if (processing_template_decl) checks with a proper is_dependent
check.

Giovanni Bajo