After overloading the type conversion operator, clang-tidy analysis errors occur.

[inschrift-spruch-raum]

#include <iostream>

class A {
public:
  int a;
  int b;

  explicit operator double(this const A& self) { return self.a + self.b; }
};

auto main(std::int32_t /*argc*/, const char* /*argv*/[]) -> std::int32_t {
  auto c = A{.a = 1, .b = 2};
  double d = double(c);
  std::cout << d;
}

clang-tidy main.cpp
5809 warnings generated.
main.cpp:12:8: warning: variable name 'c' is too short, expected at least 3 characters [readability-identifier-length]
   12 |   auto c = A{.a = 1, .b = 2};
      |        ^
main.cpp:13:3: warning: use auto when initializing with a cast to avoid duplicating the type name [hicpp-use-auto]
   13 |   double d = double(c);
      |   ^~~~~~
      |   auto
main.cpp:13:10: warning: variable name 'd' is too short, expected at least 3 characters [readability-identifier-length]
   13 |   double d = double(c);
      |          ^
main.cpp:13:14: warning: redundant cast to the same type [google-readability-casting]
   13 |   double d = double(c);
      |              ^
note: this fix will not be applied because it overlaps with another fix
main.cpp:13:14: warning: redundant explicit casting to the same type 'double' as the sub-expression, remove this casting [readability-redundant-casting]
   13 |   double d = double(c);
      |              ^~~~~~~ ~
main.cpp:8:12: note: source type originates from the invocation of this method
    8 |   explicit operator double(this const A& self) { return self.a + self.b; }
      |            ^
Suppressed 5804 warnings (5804 in non-user code).
Use -header-filter=.* to display errors from all non-system headers. Use -system-headers to display errors from system headers as well.

[llvmbot]

@llvm/issue-subscribers-clang-tidy

Author: None (inschrift-spruch-raum)

```cpp main.cpp #include <iostream>

class A {
public:
int a;
int b;

explicit operator double(this const A& self) { return self.a + self.b; }
};

auto main(std::int32_t /argc/, const char* /argv/[]) -> std::int32_t {
auto c = A{.a = 1, .b = 2};
double d = double(c);
std::cout << d;
}

clang-tidy main.cpp
5809 warnings generated.
main.cpp:12:8: warning: variable name 'c' is too short, expected at least 3 characters [readability-identifier-length]
12 | auto c = A{.a = 1, .b = 2};
| ^
main.cpp:13:3: warning: use auto when initializing with a cast to avoid duplicating the type name [hicpp-use-auto]
13 | double d = double(c);
| ^~~~~~
| auto
main.cpp:13:10: warning: variable name 'd' is too short, expected at least 3 characters [readability-identifier-length]
13 | double d = double(c);
| ^
main.cpp:13:14: warning: redundant cast to the same type [google-readability-casting]
13 | double d = double(c);
| ^
note: this fix will not be applied because it overlaps with another fix
main.cpp:13:14: warning: redundant explicit casting to the same type 'double' as the sub-expression, remove this casting [readability-redundant-casting]
13 | double d = double(c);
| ^~~~~~~ ~
main.cpp:8:12: note: source type originates from the invocation of this method
8 | explicit operator double(this const A& self) { return self.a + self.b; }
| ^
Suppressed 5804 warnings (5804 in non-user code).
Use -header-filter=.* to display errors from all non-system headers. Use -system-headers to display errors from system headers as well.

</details>

[chrchr-github]

This seems to be about a google-readability-casting false positive.
https://godbolt.org/z/r6aTdz1nG

[vbvictor]

Also applied to readability-redundant-casting https://godbolt.org/z/fqe8Kr9MT.
If we don't use this, readability-redundant-casting disappear and google-readability-casting have different error https://godbolt.org/z/MThKcqosb.

Both checks have lack of "passing this" modelling.