On Mon, May 18, 2020 at 04:50:44PM -0400, Jason Merrill via Gcc-patches wrote: > On 5/13/20 12:22 PM, Marek Polacek wrote: > > DR 2289 clarified that since structured bindings have no C compatibility > > implications, they should be unique in their declarative region, see > > [basic.scope.declarative]/4.2. > > > > The duplicate_decls hunk is the gist of the patch, but that alone would > > not be enough to detect the 'A' case: cp_parser_decomposition_declaration > > uses > > > > 13968 tree decl2 = start_decl (declarator, &decl_specs, > > SD_INITIALIZED, > > 13969 NULL_TREE, NULL_TREE, > > &elt_pushed_scope); > > > > to create the 'A' VAR_DECL but in this start_decl's grokdeclarator we > > don't do fit_decomposition_lang_decl because the declarator kind is not > > cdk_decomp > > Why isn't it? I see > > cp_declarator *declarator = make_declarator (cdk_decomp); > > a few lines up.
Right, and we use that for the underlying decomp base VAR_DECL. But each of the named variables used in a structured binding are created in the FOR_EACH_VEC_ELT loop, and that creates a cdk_id declarator for them: 13963 if (i == 0) 13964 declarator = make_id_declarator (NULL_TREE, e.get_value (), 13965 sfk_none, e.get_location ()); Marek
