https://gcc.gnu.org/bugzilla/show_bug.cgi?id=115695
Bug ID: 115695
Summary: spurious warning for -Wsign-compare with c++
Product: gcc
Version: 14.1.1
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c++
Assignee: unassigned at gcc dot gnu.org
Reporter: mtasaka at fedoraproject dot org
Target Milestone: ---
With Fedora's gcc:
```
gcc --version
gcc (GCC) 14.1.1 20240620 (Red Hat 14.1.1-6)
Copyright (C) 2024 Free Software Foundation, Inc.
This is free software; see the source for copying conditions. There is NO
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
```
```
$ cat foo.cc
#include <iostream>
#include <cstdint>
int main() {
int16_t a = 0;
std::cout << ((uint32_t)a * sizeof(int16_t)) << std::endl;
}
$ g++ -Wall -Wextra -Wsign-conversion -o foo foo.cc
foo.cc: In function ‘int main()’:
foo.cc:6:23: warning: conversion to ‘long unsigned int’ from ‘uint32_t’ {aka
‘unsigned int’} may change the sign of the result [-Wsign-conversion]
6 | std::cout << ((uint32_t)a * sizeof(int16_t)) << std::endl;
| ^~~~~~~~~~~
```
What is apparently confusing that the signness does not change, yet the warning
says this "may change the sign".
