[PATCH] PR c++/55663 - constexpr function templ instantiation considered non-const as alias templ arg

[Jason Merrill]

On 01/08/2013 08:58 AM, Dodji Seketeli wrote:
> There, when we check the argument 'the_truth<int>()' to see if it
> actually is a constant expression, in check_instantiated_arg, we fail
> to recognize its constexpr-ness b/c we just look at its TREE_CONSTANT.

The problem is that by the time we get to check_instantiated_arg, we 
should have folded the expression into something TREE_CONSTANT. 
convert_template_argument should have done that; don't we ever call that 
function for this template argument?

Jason