https://gcc.gnu.org/bugzilla/show_bug.cgi?id=120990
--- Comment #1 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
This is expected. std::function<int()> is basically wrapping the function
around like:
```
size_t bar();
int f()
{
return bar();
}
```
GCC does provide a warning with -Wconversion (though in the case of
std::function only with -Wsystem-headers which turns on a lot of conversion
warnings outside of std::function):
/opt/compiler-explorer/arm64/gcc-trunk-20250707/aarch64-unknown-linux-gnu/aarch64-unknown-linux-gnu/include/c++/16.0.0/bits/invoke.h:116:42:
warning: conversion from 'long unsigned int' to 'std::enable_if_t<true, int>'
{aka 'int'} may change value [-Wconversion]
116 | return std::__invoke_impl<__type>(__tag{},
| ~~~~~~~~~~~~~~~~~~~~~~~~~~^~~~~~~~~
117 |
std::forward<_Callable>(__fn),
|
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
118 |
std::forward<_Args>(__args)...);
|
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
