https://gcc.gnu.org/bugzilla/show_bug.cgi?id=93529
--- Comment #4 from CVS Commits <cvs-commit at gcc dot gnu.org> --- The master branch has been updated by Marek Polacek <mpola...@gcc.gnu.org>: https://gcc.gnu.org/g:73a2b8dd17dbc02c0c7e6286e90f17833aa50906 commit r11-2954-g73a2b8dd17dbc02c0c7e6286e90f17833aa50906 Author: Marek Polacek <pola...@redhat.com> Date: Thu Aug 13 14:56:13 2020 -0400 c++: Implement P1009: Array size deduction in new-expressions. This patch implements C++20 P1009, allowing code like new double[]{1,2,3}; // array bound will be deduced Since this proposal makes the initialization rules more consistent, it is applied to all previous versions of C++ (thus, effectively, all the way back to C++11). My patch is based on Jason's patch that handled the basic case. I've extended it to work with ()-init and also the string literal case. Further testing revealed that to handle stuff like new int[]{t...}; in a template, we have to consider such a NEW_EXPR type-dependent. Obviously, we first have to expand the pack to be able to deduce the number of elements in the array. Curiously, while implementing this proposal, I noticed that we fail to accept new char[4]{"abc"}; so I've assigned 77841 to self. I think the fix will depend on the build_new_1 hunk in this patch. The new tree.c function build_constructor_from_vec helps us morph a vector into a CONSTRUCTOR more efficiently. gcc/cp/ChangeLog: PR c++/93529 * call.c (build_new_method_call_1): Use build_constructor_from_vec instead of build_tree_list_vec + build_constructor_from_list. * init.c (build_new_1): Handle new char[]{"foo"}. Use build_constructor_from_vec instead of build_tree_list_vec + build_constructor_from_list. (build_new): Deduce the array size in new-expression if not present. Handle ()-init. Handle initializing an array from a string literal. * parser.c (cp_parser_new_type_id): Leave [] alone. (cp_parser_direct_new_declarator): Allow []. * pt.c (type_dependent_expression_p): In a NEW_EXPR, consider array types whose dimension has to be deduced type-dependent. gcc/ChangeLog: PR c++/93529 * tree.c (build_constructor_from_vec): New. * tree.h (build_constructor_from_vec): Declare. gcc/testsuite/ChangeLog: PR c++/93529 * g++.dg/cpp0x/sfinae4.C: Adjust expected result after P1009. * g++.dg/cpp2a/new-array1.C: New test. * g++.dg/cpp2a/new-array2.C: New test. * g++.dg/cpp2a/new-array3.C: New test. * g++.dg/cpp2a/new-array4.C: New test. Co-authored-by: Jason Merrill <ja...@redhat.com>
