Attached is a patch for constrained class templates. It's the 3rd time I've sent it.
I added some fixes for bugs discovered after the previous send, and
added support for matching constrained declarations in out-of-class
member function definitions.
2013-08-02 Andrew Sutton <andrew.n.sut...@gmail.com>
* gcc/cp/pt.c (get_class_bindings): Pass the partial specialization
for constraint evaluation. Evaluate constraints, resulting in
deduction failure on error.
(get_specializaing_template_decl), (get_specialization_constraints),
(maybe_new_partial_specialization): New.
(maybe_process_partial_specialization): Allow the creation of
new types for constrained partial specializations.
(process_partial_specialization): Modify the canonical type
of constrained partial specializations.
(resolve_template_scope): New. Match the template scope to a
specialization with appropriate constraints.
(lookup_template_class_1): Compare constraints when entering a
template scope. Check constraints on lookup. Do not explicitly check
alias constraints.
(instantiate_class_template_1): Do not explicitly check constraints
during class template instantiation.
(tsubst_decl): Instantiate the constraints of template declarations.
(more_specialized_class): Pass specializations to get_class_bindings().
Compare specialization constraints if the types are equivalent.
(most_specialized_class): Pass specialization to get_class_bndings().
* gcc/cp/decl2.c (check_class_fn): Get the decl's requirements from
either the current template reqs or from the template parameters.
Allow overloading of constrained out-of-class member definitions.
* gcc/cp/parser.c (cp_parser_parse_type_parameter): Attach
requirements to the current template parameter list.
(cp_parser_init_declarator): Parse requires clauses for out-of-class
member definitions. Be sure to restore current constraints before
exiting the function.
(cp_parser_member_declarator): Restore the previous requirements in
an early-exit branch.
(cp_parser_late_parsing_for_member): Restore constraints after
maybe_end_member_template_processing().
(cp_parser_template_declaration_after_exp): Attach constraints to
the current template parameters.
* gcc/cp/constraint.cc (reduce_template_id): Don't crash when
omitting ()'s on constraint calls.
(check_requirements): Don't evaluate dependent arguments.
(check_constraints): Don't try to evaluate when arguments are
dependent.
(equivalent_constraints): Optimize the case when a and b are the
same constraints.
--
Andrew Sutton
template.patch
Description: Binary data
