https://gcc.gnu.org/bugzilla/show_bug.cgi?id=96873
--- Comment #1 from Mateusz Pusz <mateusz.pusz at gmail dot com> ---
Similar error but in a different line happens for:
```
#include <cstdint>
template<typename CharT, std::size_t N>
struct basic_fixed_string {
CharT data_[N + 1] = {};
constexpr basic_fixed_string(CharT ch) noexcept { data_[0] = ch; }
constexpr basic_fixed_string(const CharT (&txt)[N + 1]) noexcept
{
if constexpr (N != 0)
for (std::size_t i = 0; i < N; ++i) data_[i] = txt[i];
}
[[nodiscard]] constexpr const CharT& operator[](std::size_t index) const
noexcept { return data_[index]; }
[[nodiscard]] constexpr CharT operator[](std::size_t index) noexcept { return
data_[index]; }
template<std::size_t N2>
[[nodiscard]] constexpr friend basic_fixed_string<CharT, N + N2> operator+(
const basic_fixed_string& lhs, const basic_fixed_string<CharT, N2>& rhs)
noexcept
{
CharT txt[N + N2 + 1] = {};
for(std::size_t i = 0; i != N; ++i) txt[i] = lhs[i];
for(std::size_t i = 0; i != N2; ++i) txt[N + i] = rhs[i];
return basic_fixed_string<CharT, N + N2>(txt);
}
};
template<typename CharT, std::size_t N>
basic_fixed_string(const CharT (&str)[N]) -> basic_fixed_string<CharT, N - 1>;
template<typename CharT>
basic_fixed_string(CharT) -> basic_fixed_string<CharT, 1>;
template<std::size_t N>
using fixed_string = basic_fixed_string<char, N>;
fixed_string txt = "txt";
```
