char_traits.hpp

Go to the documentation of this file.

#ifndef BSL_CHAR_TRAITS_HPP
#define BSL_CHAR_TRAITS_HPP

#include "char_type.hpp"
#include "cstdint.hpp"
#include "cstring.hpp"

namespace bsl
{

    template<typename CharT>
    class char_traits final
    {};


    template<>
    class char_traits<char_type> final
    {
    public:
        [[nodiscard]] static constexpr bool
        eq(char_type const a, char_type const b) noexcept
        {
            return a == b;
        }

        [[nodiscard]] static constexpr bool
        lt(char_type const a, char_type const b) noexcept
        {
            return a < b;
        }

        [[nodiscard]] static constexpr bsl::int32
        compare(                          // --
            char_type const *const s1,    // --
            char_type const *const s2,    // --
            bsl::uintmax const count) noexcept
        {
            return bsl::builtin_strncmp(s1, s2, count);
        }

        [[nodiscard]] static constexpr bsl::uintmax
        length(char_type const *const s) noexcept
        {
            return bsl::builtin_strlen(s);
        }

        [[nodiscard]] static constexpr char_type const *
        find(char_type const *const p, bsl::uintmax const count, char_type const &ch) noexcept
        {
            return bsl::builtin_strnchr(p, ch, count);
        }

        [[nodiscard]] static constexpr char_type
        to_char_type(bsl::intmax const c) noexcept
        {
            return static_cast<char_type>(c);
        }

        [[nodiscard]] static constexpr bsl::intmax
        to_int_type(char_type const c) noexcept
        {
            return static_cast<bsl::intmax>(c);
        }

        [[nodiscard]] static constexpr bool
        eq_int_type(bsl::intmax const c1, bsl::intmax const c2) noexcept
        {
            if ((eof() == c1) && (eof() == c2)) {
                return true;
            }

            return eq(to_char_type(c1), to_char_type(c2));
        }

        [[nodiscard]] static constexpr bsl::intmax
        eof() noexcept
        {
            constexpr bsl::intmax value_of_eof{-1};
            return value_of_eof;
        }

        [[nodiscard]] static constexpr bsl::intmax
        not_eof(bsl::intmax const e) noexcept
        {
            if (!eq_int_type(e, eof())) {
                return e;
            }

            return 0;
        }
    };
}

#endif