@@ -10620,6 +10620,7 @@ cp_parser_lambda_introducer (cp_parser* parser, tree lambda_expr)
/* Record default capture mode. "[&" "[=" "[&," "[=," */
if (cp_lexer_next_token_is (parser->lexer, CPP_AND)
+ && !cp_lexer_nth_token_is (parser->lexer, 2, CPP_ELLIPSIS)
&& !cp_lexer_nth_token_is (parser->lexer, 2, CPP_NAME)
&& !cp_lexer_nth_token_is_keyword (parser->lexer, 2, RID_THIS))
LAMBDA_EXPR_DEFAULT_CAPTURE_MODE (lambda_expr) = CPLD_REFERENCE;
@@ -10715,6 +10716,13 @@ cp_parser_lambda_introducer (cp_parser* parser, tree lambda_expr)
continue;
}
+ /* Remember whether we want to capture as a reference or not. */
+ if (cp_lexer_next_token_is (parser->lexer, CPP_AND))
+ {
+ capture_kind = BY_REFERENCE;
+ cp_lexer_consume_token (parser->lexer);
+ }
+
bool init_pack_expansion = false;
location_t ellipsis_loc = UNKNOWN_LOCATION;
if (cp_lexer_next_token_is (parser->lexer, CPP_ELLIPSIS))
@@ -10727,9 +10735,12 @@ cp_parser_lambda_introducer (cp_parser* parser, tree lambda_expr)
init_pack_expansion = true;
}
- /* Remember whether we want to capture as a reference or not. */
- if (cp_lexer_next_token_is (parser->lexer, CPP_AND))
+ /* Early C++20 drafts had ...& instead of &...; be forgiving. */
+ if (init_pack_expansion && capture_kind != BY_REFERENCE
+ && cp_lexer_next_token_is (parser->lexer, CPP_AND))
{
+ pedwarn (cp_lexer_peek_token (parser->lexer)->location,
+ 0, "%<&%> should come before %<...%>");
capture_kind = BY_REFERENCE;
cp_lexer_consume_token (parser->lexer);
}
new file mode 100644
@@ -0,0 +1,10 @@
+// P2095R0
+// { dg-do compile { target c++2a } }
+// { dg-options "" }
+
+template <class... T>
+void f(T... t)
+{
+ [&...x=t]{};
+ [...&x=t]{}; // { dg-warning "7:&" }
+}