On 3/10/22 04:34, Jakub Jelinek wrote:
Hi!wg21.link/p2128 removed "with exactly one parameter" from over.sub section. grok_op_properties has for that the last 2 lines in: case OVL_OP_FLAG_BINARY: if (arity != 2) { if (operator_code == ARRAY_REF && cxx_dialect >= cxx23) break; but unfortunately it isn't enough, we reject variadic operator[] earlier. The following patch accepts variadic operator[] for C++23 too. Bootstrapped/regtested on x86_64-linux and i686-linux, ok for trunk?
OK.
2022-03-10 Jakub Jelinek <ja...@redhat.com> PR c++/103460 * decl.cc (grok_op_properties): Allow variadic operator[] for C++23. * g++.dg/cpp23/subscript7.C: New test. --- gcc/cp/decl.cc.jj 2022-03-09 15:24:57.285926439 +0100 +++ gcc/cp/decl.cc 2022-03-09 16:56:41.053901657 +0100 @@ -15214,6 +15214,9 @@ grok_op_properties (tree decl, bool comp if (!arg) { /* Variadic. */ + if (operator_code == ARRAY_REF && cxx_dialect >= cxx23) + break; + error_at (loc, "%qD must not have variable number of arguments", decl); return false; @@ -15289,7 +15292,8 @@ grok_op_properties (tree decl, bool comp }/* There can be no default arguments. */- for (tree arg = argtypes; arg != void_list_node; arg = TREE_CHAIN (arg)) + for (tree arg = argtypes; arg && arg != void_list_node; + arg = TREE_CHAIN (arg)) if (TREE_PURPOSE (arg)) { TREE_PURPOSE (arg) = NULL_TREE; --- gcc/testsuite/g++.dg/cpp23/subscript7.C.jj 2022-03-09 17:02:22.915179262 +0100 +++ gcc/testsuite/g++.dg/cpp23/subscript7.C 2022-03-09 17:02:18.446240994 +0100 @@ -0,0 +1,17 @@ +// PR c++/103460 +// { dg-do compile } +// { dg-options "-std=c++23" } + +struct S { + int &operator[] (int, ...); +} s; +struct T { + int &operator[] (auto...); +} t; +struct U { + int &operator[] (...); +} u; + +int a = s[1] + s[2, 1] + s[3, 2, 1] + s[4, 3, 2, 1] + + t[0.0] + t[nullptr, s, 42] + + u[] + u[42] + u[1.5L, 1LL]; Jakub
