diff options
Diffstat (limited to 'to_string.hpp')
| -rw-r--r-- | to_string.hpp | 27 |
1 files changed, 16 insertions, 11 deletions
diff --git a/to_string.hpp b/to_string.hpp index 01a4c4d..d0a4dbe 100644 --- a/to_string.hpp +++ b/to_string.hpp @@ -7,11 +7,12 @@ #ifndef TCSULLIVAN_TO_STRING_HPP_ #define TCSULLIVAN_TO_STRING_HPP_ +#include <cstdint> #include <type_traits> namespace constexpr_to_string { -inline constexpr char digits[] = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ"; +constexpr char digits[] = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ"; /** * @struct to_string_t @@ -19,17 +20,17 @@ inline constexpr char digits[] = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ"; * @tparam N Number to convert * @tparam base Desired base, can be from 2 to 36 */ -template<auto N, int base, typename char_type, - std::enable_if_t<std::is_integral_v<decltype(N)>, int> = 0, +template<std::intmax_t N, int base, typename char_type, std::enable_if_t<(base > 1 && base < sizeof(digits)), int> = 0> class to_string_t { - // The lambda calculates what the string length of N will be, so that `buf` - // fits to the number perfectly. - char_type buf[([]() constexpr noexcept { - unsigned int len = N > 0 ? 1 : 2; - for (auto n = N; n; len++, n /= base); - return len; - }())] = {}; + + constexpr static auto buflen() noexcept { + unsigned int len = N > 0 ? 1 : 2; + for (auto n = N; n; len++, n /= base); + return len; + } + + char_type buf[buflen()] = {}; public: /** @@ -38,6 +39,7 @@ class to_string_t { constexpr to_string_t() noexcept { auto ptr = end(); *--ptr = '\0'; + if (N != 0) { for (auto n = N; n; n /= base) *--ptr = digits[(N < 0 ? -1 : 1) * (n % base)]; @@ -53,6 +55,7 @@ class to_string_t { constexpr operator const char_type *() const noexcept { return buf; } constexpr auto size() const noexcept { return sizeof(buf) / sizeof(buf[0]); } + // Element access constexpr auto data() noexcept { return buf; } constexpr const auto data() const noexcept { return buf; } @@ -62,6 +65,7 @@ class to_string_t { constexpr const auto& front() const noexcept { return buf[0]; } constexpr auto& back() noexcept { return buf[size() - 1]; } constexpr const auto& back() const noexcept { return buf[size() - 1]; } + // Iterators constexpr auto begin() noexcept { return buf; } constexpr const auto begin() const noexcept { return buf; } @@ -74,7 +78,8 @@ class to_string_t { /** * Simplifies use of `to_string_t` from `to_string_t<N>()` to `to_string<N>`. */ -template<auto N, int base = 10, typename char_type = char> +template<std::intmax_t N, int base = 10, typename char_type = char> constexpr constexpr_to_string::to_string_t<N, base, char_type> to_string; #endif // TCSULLIVAN_TO_STRING_HPP_ + |