ctai_string_front_0.cpp

namespace details
{
    template <typename>
    struct string_front_impl;

    template <char front, char ...chars>
    struct string_front_impl<string<front, chars...>>
    {
        static constexpr auto value = front;
    };
}

template <typename s>
constexpr auto string_front = details::string_front_impl<s>::value;