https://gcc.gnu.org/bugzilla/show_bug.cgi?id=120548
Bug ID: 120548
Summary: std::format confuses a negative sign for a thousands
digit when formatting floating point numbers
Product: gcc
Version: 15.1.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c++
Assignee: unassigned at gcc dot gnu.org
Reporter: drew.dormann at gmail dot com
Target Milestone: ---
A minimal reproducible example.
```
#include <format>
#include <iostream>
int main()
{
std::cout << std::format( std::locale("en_US.UTF-8"), "{:L}", -123.45 );
}
```
I expect this code to display `-123.45`. I'm asking for thousands separators,
but there is no thousands digit.
Instead, I see:
-,123.45
This differs from the behavior of MSVC, clang's libc++, and fmt::format, which
all produce the result I expected.
