https://gcc.gnu.org/bugzilla/show_bug.cgi?id=112341
Arsen Arsenović <arsen at gcc dot gnu.org> changed:
What |Removed |Added
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CC| |arsen at gcc dot gnu.org
--- Comment #2 from Arsen Arsenović <arsen at gcc dot gnu.org> ---
this is because the '(auto)' template parameter suppresses CO_AWAIT expansion,
so we enter the following block in coroutine.cc:finish_co_await_expr
/* Defer expansion when we are processing a template.
FIXME: If the coroutine function's type is not dependent, and the operand
is not dependent, we should determine the type of the co_await expression
using the DEPENDENT_EXPR wrapper machinery. That allows us to determine
the subexpression type, but leave its operand unchanged and then
instantiate it later. */
if (processing_template_decl)
{
tree aw_expr = build5_loc (kw, CO_AWAIT_EXPR, unknown_type_node, expr,
NULL_TREE, NULL_TREE, NULL_TREE,
integer_zero_node);
TREE_SIDE_EFFECTS (aw_expr) = true;
return aw_expr;
}
... which sets the type of the co_await to the unknown type
