https://gcc.gnu.org/bugzilla/show_bug.cgi?id=119661
Bug ID: 119661
Summary: Possible "accepts invalid": member access into
incomplete type 'struct s'
Product: gcc
Version: 14.2.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c++
Assignee: unassigned at gcc dot gnu.org
Reporter: pavel.morozkin at gmail dot com
Target Milestone: ---
Note: this may be a duplicate.
This C++ code:
struct s
{
int x;
int y[sizeof((struct s*)0)->x];
};
compiled with g++ -std=c++26 -pedantic -Wall -Wextra produces:
<nothing>
while compiled with clang -std=c++26 -pedantic -Wall -Wextra produces:
<source>:4:31: error: member access into incomplete type 'struct s'
4 | int y[sizeof((struct s*)0)->x];
| ^
<source>:1:8: note: definition of 's' is not complete until the closing '}'
1 | struct s
| ^
Online demo: https://gcc.godbolt.org/z/nvrrM7zez.
Who is correct? (Please elaborate by quoting the C++ standard.)
Originates from: https://stackoverflow.com/q/79538353/1778275.
