decomp = &decomp_d;
decomp->count = tree_to_uhwi (TREE_OPERAND (v, 1)) + 1;
decomp->decl = d;
+ bool seen_name_independent_decl = false;
for (unsigned int i = 0; i < decomp->count;
i++, d = DECL_CHAIN (d))
{
+ if (name_independent_decl_p (d))
+ {
+ /* If there is more than one _ decl in
+ the structured binding, just push and move it
+ away once. */
+ if (seen_name_independent_decl)
+ continue;
+ seen_name_independent_decl = true;
+ }
tree name = DECL_NAME (d);
names.safe_push (name);
bindings.safe_push (IDENTIFIER_BINDING (name));
--- /dev/null
+// PR c++/115586
+// { dg-do compile { target c++11 } }
+// { dg-options "" }
+
+struct S { int a, b, c; };
+
+void
+foo ()
+{
+ S s[4] = {};
+ for (auto [_, _, a] : s) // { dg-warning "name-independent declarations only available with" "" { target c++23_down } }
+ ++_; // { dg-warning "structured bindings only available with" "" { target c++14_down } .-1 }
+ // { dg-error "reference to '_' is ambiguous" "" { target *-*-* } .-1 }
+ for (auto _ : s)
+ ++_.b;
+ for (auto [a, _, b] : s) // { dg-warning "structured bindings only available with" "" { target c++14_down } }
+ ++_;
+ for (auto [_, _, a] : s) // { dg-warning "name-independent declarations only available with" "" { target c++23_down } }
+ { // { dg-warning "structured bindings only available with" "" { target c++14_down } .-1 }
+ ++_; // { dg-error "reference to '_' is ambiguous" }
+ }
+ for (auto _ : s)
+ {
+ ++_.b;
+ int _ = 2; // { dg-warning "name-independent declarations only available with" "" { target c++23_down } }
+ ++_; // { dg-error "reference to '_' is ambiguous" }
+ }
+ for (auto [a, _, b] : s) // { dg-warning "structured bindings only available with" "" { target c++14_down } }
+ {
+ ++_;
+ int _ = ++b; // { dg-warning "name-independent declarations only available with" "" { target c++23_down } }
+ ++_; // { dg-error "reference to '_' is ambiguous" }
+ }
+}
+
+void
+bar ()
+{
+ S s[4] = {};
+ auto [_, c, _] = s[0]; // { dg-warning "name-independent declarations only available with" "" { target c++23_down } }
+ ++_; // { dg-warning "structured bindings only available with" "" { target c++14_down } .-1 }
+ // { dg-error "reference to '_' is ambiguous" "" { target *-*-* } .-1 }
+ for (auto [a, _, _] : s) // { dg-warning "name-independent declarations only available with" "" { target c++23_down } }
+ ++_; // { dg-warning "structured bindings only available with" "" { target c++14_down } .-1 }
+ // { dg-error "reference to '_' is ambiguous" "" { target *-*-* } .-1 }
+ for (auto _ : s)
+ ++_.c;
+ for (auto [a, b, _] : s) // { dg-warning "structured bindings only available with" "" { target c++14_down } }
+ ++_;
+ for (auto [a, _, _] : s) // { dg-warning "name-independent declarations only available with" "" { target c++23_down } }
+ { // { dg-warning "structured bindings only available with" "" { target c++14_down } .-1 }
+ ++_; // { dg-error "reference to '_' is ambiguous" }
+ ++a;
+ }
+ for (auto _ : s)
+ int _ = 5; // { dg-warning "name-independent declarations only available with" "" { target c++23_down } }
+ for (auto [a, b, _] : s) // { dg-warning "structured bindings only available with" "" { target c++14_down } }
+ {
+ ++_;
+ int _ = a + b; // { dg-warning "name-independent declarations only available with" "" { target c++23_down } }
+ ++_; // { dg-error "reference to '_' is ambiguous" }
+ }
+}
--- /dev/null
+// PR c++/115586
+// { dg-do compile { target c++11 } }
+// { dg-options "-Wunused-variable -Wunused-but-set-variable -Wunused-parameter -Wshadow" }
+
+struct S { int a, b, c; };
+
+void
+foo ()
+{
+ S s[4] = {};
+ for (auto [_, _, a] : s) // { dg-warning "name-independent declarations only available with" "" { target c++23_down } }
+ ++a; // { dg-warning "structured bindings only available with" "" { target c++14_down } .-1 }
+ for (auto _ : s)
+ ++_.b;
+ for (auto [a, _, b] : s) // { dg-warning "structured bindings only available with" "" { target c++14_down } }
+ ++a;
+ for (auto [_, _, a] : s) // { dg-warning "name-independent declarations only available with" "" { target c++23_down } }
+ int _ = ++a; // { dg-warning "structured bindings only available with" "" { target c++14_down } .-1 }
+ for (auto _ : s)
+ {
+ int _ = 2; // { dg-warning "name-independent declarations only available with" "" { target c++23_down } }
+ }
+ for (auto [a, _, b] : s) // { dg-warning "structured bindings only available with" "" { target c++14_down } }
+ int _ = ++b; // { dg-warning "name-independent declarations only available with" "" { target c++23_down } }
+}
+
+void
+bar ()
+{
+ S s[4] = {};
+ auto [_, c, _] = s[0]; // { dg-warning "name-independent declarations only available with" "" { target c++23_down } }
+ ++c; // { dg-warning "structured bindings only available with" "" { target c++14_down } .-1 }
+ for (auto [a, _, _] : s) // { dg-warning "name-independent declarations only available with" "" { target c++23_down } }
+ ++a; // { dg-warning "structured bindings only available with" "" { target c++14_down } .-1 }
+ for (auto _ : s)
+ ++_.c;
+ for (auto [a, b, _] : s) // { dg-warning "structured bindings only available with" "" { target c++14_down } }
+ ++b;
+ for (auto [a, _, _] : s) // { dg-warning "name-independent declarations only available with" "" { target c++23_down } }
+ { // { dg-warning "structured bindings only available with" "" { target c++14_down } .-1 }
+ int _ = ++a;
+ }
+ for (auto _ : s)
+ int _ = 5; // { dg-warning "name-independent declarations only available with" "" { target c++23_down } }
+ for (auto [a, b, _] : s) // { dg-warning "structured bindings only available with" "" { target c++14_down } }
+ {
+ int _ = a + b; // { dg-warning "name-independent declarations only available with" "" { target c++23_down } }
+ }
+}