https://gcc.gnu.org/bugzilla/show_bug.cgi?id=125978
Bug ID: 125978
Summary: contracts: violation comment() overly verbose with
reference returning subscript operators
Product: gcc
Version: 17.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c++
Assignee: unassigned at gcc dot gnu.org
Reporter: ivan.lazaric.gcc at gmail dot com
Target Milestone: ---
```cpp
struct A {
int x = 42;
const int& operator[](int) const { return x; }
};
int main() {
A foo;
contract_assert(foo[0] == 67);
}
```
Compilation flags: "-std=c++26 -fcontracts"
Running this program, output:
```
contract violation in function int main() at foo.cpp:8: (((int)((const A*)(&
foo))->A::operator[](0)) == 67)
[assertion_kind: assert, semantic: enforce, mode: predicate_false, terminating:
yes]
terminate called without an active exception
Aborted (core dumped)
```
First line is overly noisy
Compare this to a value returning operator:
```cpp
struct A {
int x = 42;
int operator[](int) const { return x; }
};
int main() {
A foo;
contract_assert(foo[0] == 67);
}
```
Running it produces:
```
contract violation in function int main() at foo.cpp:8: foo[0] == 67
[assertion_kind: assert, semantic: enforce, mode: predicate_false, terminating:
yes]
terminate called without an active exception
Aborted (core dumped)
```
The comment() in first line is much more clear IMO
