dev v0.3.0

.gitignore

@@ -1,4 +1,5 @@
 build/
+.vscode/
 
 ### C++ gitignore ###
 # Prerequisites

README.md

@@ -21,10 +21,12 @@
 ## What is Magic Enum?
 
 Header-only C++17 library provides Enum-to-String and String-to-Enum functions.
-* `magic_enum::enum_to_string` obtains string enum name from enum variable.
-* `magic_enum::enum_from_string` obtains enum value from enum string name.
-* `magic_enum::enum_to_sequence` obtains value enum sequence.
-* `magic_enum::enum_to_string_sequence` obtains string enum name sequence.
+* `magic_enum::enum_cast` obtains enum value from string or integer.
+* `magic_enum::enum_value` obtains indexed access to enum value.
+* `magic_enum::enum_values` obtains enum value sequence.
+* `magic_enum::enum_count` obtains number of enum values.
+* `magic_enum::enum_name` obtains string name from enum value.
+* `magic_enum::enum_names` obtains string enum name sequence.
 
 ## Features
 
@@ -34,56 +36,84 @@ Header-only C++17 library provides Enum-to-String and String-to-Enum functions.
 * Compile-time
 * Enum to string
 * String to enum
+* Works with any enum type
 
 ## [Examples](example/example.cpp)
 
-* Enum variable to string enum name
+* Enum value to string
   ```cpp
-  auto color = Color::RED;
-  auto color_name = magic_enum::enum_to_string(color);
+  Color color = Color::RED;
+  auto color_name = magic_enum::enum_name(color);
   if (color_name.has_value()) {
     // color_name.value() -> "RED"
   }
   ```
 
-* Static storage enum variable to string enum name
+* Static storage enum variable to string
   ```cpp
-  constexpr auto color = Color::BLUE;
-  constexpr auto color_name = magic_enum::enum_to_string<color>();
+  constexpr Color color = Color::BLUE;
+  constexpr auto color_name = magic_enum::enum_name(color);
   if (color_name.has_value()) {
     // color_name.value() -> "BLUE"
   }
   ```
 
-* String enum name to enum value
+* String to enum value
   ```cpp
-  constexpr auto color = magic_enum::enum_from_string<Color>("GREEN");
+  constexpr auto color = magic_enum::enum_cast<Color>("GREEN");
   if (color.has_value()) {
     // color.value() -> Color::GREEN
   }
   ```
 
-* Enum to value sequence
+* Integer to enum value
   ```cpp
-  constexpr auto colors = magic_enum::enum_to_sequence<Color>();
+  constexpr auto color = magic_enum::enum_cast<Color>(0);
+  if (color.has_value()) {
+    // color.value() -> Color::RED
+  }
+  ```
+
+* Indexed access to enum value
+  ```cpp
+  constexpr Color color_value = magic_enum::enum_value<Color>(0);
+  // color_element -> Color::RED
+  ```
+
+* Enum value sequence
+  ```cpp
+  constexpr auto colors = magic_enum::enum_values<Color>();
   // colors -> {Color::RED, Color::BLUE, Color::GREEN}
   ```
 
-* Enum to string enum name sequence
+* Number of enum elements
   ```cpp
-  constexpr auto color_names = magic_enum::enum_to_string_sequence<Color>();
+  constexpr std::size_t color_size = magic_enum::enum_count<Color>();
+  // color_size -> 3
+  ```
+
+* Enum string sequence
+  ```cpp
+  constexpr auto color_names = magic_enum::enum_names<Color>();
   // color_names -> {"RED", "BLUE", "GREEN"}
   ```
 
+* Stream operator for enum
+  ```cpp
+  using namespace magic_enum::ops; // out-of-the-box stream operator for enums.
+  Color color = Color::BLUE;
+  std::cout << color << std::endl; // "BLUE"
+  ```
+
 ## Remarks
 
-* `magic_enum::enum_to_string` returns `std::optional<std::string_view>`, using `has_value()` to check contains enum name and `value()` to get the enum name. If enum value does not have name or out of range `MAGIC_ENUM_RANGE`, returns `std::nullopt`.
+* `magic_enum::enum_cast` returns `std::optional<E>`, using `has_value()` to check contains enum value and `value()` to get the enum value.
 
-* `magic_enum::enum_from_string` returns `std::optional<E>`, using `has_value()` to check contains enum value and `value()` to get the enum value. If enum value does not have name or out of range `MAGIC_ENUM_RANGE`, returns `std::nullopt`.
+* `magic_enum::enum_values` returns `std::array<E, N>` with all enum value, sorted by enum value.
 
-* `magic_enum::enum_to_sequence` returns `std::array<E, N>` with all value enum, sorted by enum value.
+* `magic_enum::enum_name` returns `std::optional<std::string_view>`, using `has_value()` to check contains enum name and `value()` to get the enum name.
 
-* `magic_enum::enum_to_string_sequence` returns `std::array<std::string_view, N>` with all string enum name, sorted by enum value.
+* `magic_enum::enum_names` returns `std::array<std::string_view, N>` with all string enum name, sorted by enum value.
 
 * Enum value must be in range `(-MAGIC_ENUM_RANGE, MAGIC_ENUM_RANGE)`. By default `MAGIC_ENUM_RANGE = 128`. If you need larger range, redefine the macro `MAGIC_ENUM_RANGE`.
   ```cpp

example/example.cpp

@@ -20,45 +20,57 @@
 // OUT OF OR IN CONNECTION WITH THE SOFTWARE  OR THE USE OR OTHER DEALINGS IN THE
 // SOFTWARE.
 
-#include <magic_enum.hpp>
-
 #include <iostream>
+#include <sstream>
+
+#include <magic_enum.hpp>
 
 enum Color { RED = -10, BLUE = 0, GREEN = 10 };
 
 int main() {
-  // Enum variable to string enum name.
-  auto c1 = Color::RED;
-  auto c1_name = magic_enum::enum_to_string(c1);
+  // Enum variable to string name.
+  Color c1 = Color::RED;
+  auto c1_name = magic_enum::enum_name(c1);
   if (c1_name.has_value()) {
     std::cout << c1_name.value() << std::endl; // RED
   }
 
-  // String enum name to enum variable.
-  auto c2 = magic_enum::enum_from_string<Color>("GREEN");
-  if (c2.has_value() && c2.value() == Color::GREEN) {
-    std::cout << "GREEN = " << c2.value() << std::endl; // GREEN = 10
-  }
-
-  // Static storage enum variable to string enum name.
-  constexpr auto c3 = Color::BLUE;
-  constexpr auto c3_name = magic_enum::enum_to_string<c3>();
-  if (c3_name.has_value()) {
-    std::cout << c3_name.value() << std::endl; // BLUE
-  }
-
-  constexpr auto colors = magic_enum::enum_to_sequence<Color>();
-  std::cout << "Colors:";
-  for (auto e : colors) {
-    std::cout << " " << magic_enum::enum_to_string(e).value();
+  // String enum name sequence.
+  constexpr auto color_names = magic_enum::enum_names<Color>();
+  std::cout << "Color names:";
+  for (auto n : color_names) {
+    std::cout << " " << n;
   }
   std::cout << std::endl;
-  // Color sequence: RED BLUE GREEN
+  // Color names: RED BLUE GREEN
 
-  constexpr auto color_names = magic_enum::enum_to_string_sequence<Color>();
-  std::cout << "Color names:";
-  for (auto e : color_names) {
-    std::cout << " " << e;
+  // String name to enum value.
+  auto c2 = magic_enum::enum_cast<Color>("BLUE");
+  if (c2.has_value() && c2.value() == Color::BLUE) {
+    std::cout << "BLUE = " << c2.value() << std::endl; // BLUE = 0
+  }
+
+  // Integer value to enum value.
+  auto c3 = magic_enum::enum_cast<Color>(10);
+  if (c3.has_value() && c3.value() == Color::GREEN) {
+    std::cout << "GREEN = " << c3.value() << std::endl; // GREEN = 10
+  }
+
+  using namespace magic_enum::ops; // out-of-the-box stream operator for enums.
+  // ostream operator for enum.
+  std::cout << "Color: " << c1 << " " << c2 << " " << c3 << std::endl; // Color: RED BLUE GREEN
+
+  // Number of enum values.
+  std::cout << "Color enum size: " << magic_enum::enum_count<Color>() << std::endl; // Color enum size: 3
+
+  // Indexed access to enum value.
+  std::cout << "Color[0] = " << magic_enum::enum_value<Color>(0) << std::endl; // Color[0] = RED
+
+  // Enum value sequence.
+  constexpr auto colors = magic_enum::enum_values<Color>();
+  std::cout << "Colors sequence:";
+  for (Color c : colors) {
+    std::cout << " " << c; // ostream operator for enum.
   }
   std::cout << std::endl;
   // Color sequence: RED BLUE GREEN

include/magic_enum.hpp

@@ -5,7 +5,7 @@
 // | |  | | (_| | (_| | | (__  | |____| | | | |_| | | | | | | | |____|_|   |_|
 // |_|  |_|\__,_|\__, |_|\___| |______|_| |_|\__,_|_| |_| |_|  \_____|
 //                __/ | https://github.com/Neargye/magic_enum
-//               |___/  vesion 0.2.0
+//               |___/  vesion 0.3.0-dev
 //
 // Licensed under the MIT License <http://opensource.org/licenses/MIT>.
 // SPDX-License-Identifier: MIT
@@ -31,13 +31,16 @@
 
 #pragma once
 
+#include <algorithm>
+#include <array>
+#include <cassert>
 #include <cstddef>
-#include <type_traits>
+#include <iosfwd>
 #include <limits>
 #include <string_view>
 #include <optional>
-#include <array>
-#include <algorithm>
+#include <type_traits>
+#include <utility>
 
 // Enum value must be in range (-MAGIC_ENUM_RANGE, MAGIC_ENUM_RANGE). If you need a larger range, redefine the macro MAGIC_ENUM_RANGE.
 #if !defined(MAGIC_ENUM_RANGE)
@@ -53,13 +56,28 @@ static_assert(MAGIC_ENUM_RANGE < std::numeric_limits<int>::max(),
 
 namespace detail {
 
+template <typename E>
+struct enum_range final {
+  using D = std::decay_t<E>;
+  static_assert(std::is_enum_v<D>, "magic_enum::detail::enum_range require enum type.");
+  using U = std::underlying_type_t<D>;
+  using C = std::common_type_t<int, U>;
+  static constexpr int min = std::max<C>(std::is_signed_v<U> ? -MAGIC_ENUM_RANGE : 0, std::numeric_limits<U>::min());
+  static constexpr int max = std::min<C>(MAGIC_ENUM_RANGE, std::numeric_limits<U>::max());
+  static constexpr auto sequence = std::make_integer_sequence<int, max - min + 1>{};
+
+  static constexpr bool contains(int value) noexcept {
+    return static_cast<int>(value) <= enum_range<D>::max && static_cast<int>(value) >= enum_range<D>::min;
+  }
+};
+
 [[nodiscard]] constexpr bool is_name_char(char c, bool front) noexcept {
   return (!front && c >= '0' && c <= '9') || (c >= 'a' && c <= 'z') || (c >= 'A' && c <= 'Z') || c == '_';
 }
 
 template <typename E, E V>
-[[nodiscard]] constexpr std::string_view enum_to_string_impl() noexcept {
-  static_assert(std::is_enum_v<E>, "magic_enum::enum_to_string require enum type.");
+[[nodiscard]] constexpr std::string_view name_impl() noexcept {
+  static_assert(std::is_enum_v<E>, "magic_enum::detail::name_impl require enum type.");
 #if defined(__clang__)
   std::string_view name{__PRETTY_FUNCTION__};
   constexpr auto suffix = sizeof("]") - 1;
@@ -90,128 +108,167 @@ template <typename E, E V>
 #endif
 }
 
-template <typename E, int O, int... I>
-[[nodiscard]] constexpr std::string_view enum_to_string_impl(int value, std::integer_sequence<int, I...>) noexcept {
-  static_assert(std::is_enum_v<E>, "magic_enum::enum_to_string require enum type.");
-  constexpr int n = sizeof...(I);
-  constexpr std::array<std::string_view, n> names{{enum_to_string_impl<E, static_cast<E>(I + O)>()...}};
+template <typename E, int... I>
+[[nodiscard]] constexpr decltype(auto) strings_impl(std::integer_sequence<int, I...>) noexcept {
+  static_assert(std::is_enum_v<E>, "magic_enum::detail::strings_impl require enum type.");
+  constexpr std::array<std::string_view, sizeof...(I)> names{{name_impl<E, static_cast<E>(I + enum_range<E>::min)>()...}};
 
-  return names[value - O];
+  return names;
 }
 
-template <typename E, int O, int... I>
-[[nodiscard]] constexpr std::optional<E> enum_from_string_impl(std::string_view name, std::integer_sequence<int, I...>) noexcept {
-  static_assert(std::is_enum_v<E>, "magic_enum::enum_from_string require enum type.");
-  std::optional<E> value{std::nullopt};
-  (void)(((enum_to_string_impl<E, static_cast<E>(I + O)>() == name) ? (value = static_cast<E>(I + O), false) : true) && ...);
+template <typename E>
+[[nodiscard]] constexpr std::string_view name_impl(int value) noexcept {
+  static_assert(std::is_enum_v<E>, "magic_enum::detail::name_impl require enum type.");
+  constexpr auto names = strings_impl<E>(enum_range<E>::sequence);
 
-  return value;
+  return enum_range<E>::contains(value) ? names[value - enum_range<E>::min] : std::string_view{};
 }
 
-template <typename E, int O, int... I>
-[[nodiscard]] constexpr decltype(auto) enum_to_sequence_impl(std::integer_sequence<int, I...>) noexcept {
-  static_assert(std::is_enum_v<E>, "magic_enum::enum_to_sequence require enum type.");
+template <typename E, int... I>
+[[nodiscard]] constexpr decltype(auto) values_impl(std::integer_sequence<int, I...>) noexcept {
+  static_assert(std::is_enum_v<E>, "magic_enum::detail::values_impl require enum type.");
   constexpr int n = sizeof...(I);
-  constexpr std::array<bool, n> valid{{!enum_to_string_impl<E, static_cast<E>(I + O)>().empty()...}};
+  constexpr std::array<bool, n> valid{{!name_impl<E, static_cast<E>(I + enum_range<E>::min)>().empty()...}};
   constexpr int num_valid = ((valid[I] ? 1 : 0) + ...);
 
-  std::array<E, num_valid> sequence{};
+  std::array<E, num_valid> enums{};
   for (int i = 0, v = 0; i < n && v < num_valid; ++i) {
     if (valid[i]) {
-      sequence[v++] = static_cast<E>(i + O);
+      enums[v++] = static_cast<E>(i + enum_range<E>::min);
     }
   }
 
-  return sequence;
+  return enums;
 }
 
-template <typename E, int O, int... I>
-[[nodiscard]] constexpr decltype(auto) enum_to_string_sequence_impl(std::integer_sequence<int, I...> s) noexcept {
-  static_assert(std::is_enum_v<E>, "magic_enum::enum_to_string_sequence require enum type.");
-  constexpr int n = sizeof...(I);
-  constexpr std::array<bool, n> valid{{!enum_to_string_impl<E, static_cast<E>(I + O)>().empty()...}};
-  constexpr int num_valid = ((valid[I] ? 1 : 0) + ...);
+template <typename E, std::size_t... I>
+[[nodiscard]] constexpr decltype(auto) names_impl(std::integer_sequence<std::size_t, I...>) noexcept {
+  static_assert(std::is_enum_v<E>, "magic_enum::detail::names_impl require enum type.");
+  constexpr auto enums = values_impl<E>(enum_range<E>::sequence);
+  constexpr std::array<std::string_view, sizeof...(I)> names{{name_impl<E, enums[I]>()...}};
 
-  std::array<std::string_view, num_valid> sequence{};
-  for (int i = 0, v = 0; i < n && v < num_valid; ++i) {
-    if (valid[i]) {
-      sequence[v++] = enum_to_string_impl<E, O>(i + O, s);
-    }
-  }
-
-  return sequence;
+  return names;
 }
 
-} // namespace detail
+template <typename E>
+[[nodiscard]] constexpr std::optional<E> enum_cast_impl(std::string_view value) noexcept {
+  static_assert(std::is_enum_v<E>, "magic_enum::detail::enum_cast_impl require enum type.");
+  constexpr auto values = values_impl<E>(enum_range<E>::sequence);
+  constexpr auto count = values.size();
+  constexpr auto names = names_impl<E>(std::make_index_sequence<count>{});
 
-// enum_to_string(enum) obtains string enum name from enum variable.
-template <typename T, typename = std::enable_if_t<std::is_enum_v<std::decay_t<T>>>>
-[[nodiscard]] constexpr std::optional<std::string_view> enum_to_string(T value) noexcept {
-  using D = std::decay_t<T>;
-  using U = std::underlying_type_t<D>;
-  using C = std::common_type_t<int, U>;
-  constexpr int min = std::max<C>(std::is_signed_v<U> ? -MAGIC_ENUM_RANGE : 0, std::numeric_limits<U>::min());
-  constexpr int max = std::min<C>(MAGIC_ENUM_RANGE, std::numeric_limits<U>::max());
-  constexpr int range = max - min + 1;
-
-  if (static_cast<int>(value) > max || static_cast<int>(value) < min) {
-    return std::nullopt; // Enum value out of range.
+  for (std::size_t i = 0; i < count; ++i) {
+    if (names[i] == value) {
+      return values[i];
+    }
   }
 
-  const auto name = detail::enum_to_string_impl<D, min>(static_cast<int>(value), std::make_integer_sequence<int, range>{});
-  if (name.empty()) {
-    return std::nullopt;
+  return std::nullopt; // Invalid value or out of range.
+}
+
+template<class E>
+using enable_if_enum_t = typename std::enable_if<std::is_enum_v<std::decay_t<E>>>::type;
+
+} // namespace magic_enum::detail
+
+// Obtains enum value from enum string name.
+template <typename E, typename = detail::enable_if_enum_t<E>>
+[[nodiscard]] constexpr std::optional<E> enum_cast(std::string_view value) noexcept {
+  using D = std::decay_t<E>;
+
+  return detail::enum_cast_impl<D>(value);
+}
+
+// Obtains enum value from integer value.
+template <typename E, typename = detail::enable_if_enum_t<E>>
+[[nodiscard]] constexpr std::optional<E> enum_cast(std::underlying_type_t<E> value) noexcept {
+  using D = std::decay_t<E>;
+
+  if (detail::name_impl<D>(static_cast<int>(value)).empty()) {
+    return std::nullopt; // Invalid value or out of range.
   } else {
-    return name; // Enum value does not have name.
+    return static_cast<D>(value);
   }
 }
 
-// enum_to_string<enum>() obtains string enum name from static storage enum variable.
-template <auto V, typename = std::enable_if_t<std::is_enum_v<std::decay_t<decltype(V)>>>>
-[[nodiscard]] constexpr std::optional<std::string_view> enum_to_string() noexcept {
-  constexpr auto name = detail::enum_to_string_impl<decltype(V), V>();
+// Obtains indexed access to enum element.
+template<typename E, typename = detail::enable_if_enum_t<E>>
+[[nodiscard]] constexpr E enum_value(std::size_t i) noexcept {
+  using D = std::decay_t<E>;
+  constexpr auto values = detail::values_impl<D>(detail::enum_range<D>::sequence);
+
+  return assert(i < values.size()), values[i];
+}
+
+// Obtains value enum sequence.
+template <typename E, typename = detail::enable_if_enum_t<E>>
+[[nodiscard]] constexpr decltype(auto) enum_values() noexcept {
+  using D = std::decay_t<E>;
+  constexpr auto values = detail::values_impl<D>(detail::enum_range<D>::sequence);
+
+  return values;
+}
+
+// Obtains number of enum elements.
+template <typename E, typename = detail::enable_if_enum_t<E>>
+[[nodiscard]] constexpr std::size_t enum_count() noexcept {
+  using D = std::decay_t<E>;
+  constexpr auto count = detail::values_impl<D>(detail::enum_range<D>::sequence).size();
+
+  return count;
+}
+
+// Obtains string enum name from enum value.
+template <typename E, typename = detail::enable_if_enum_t<E>>
+[[nodiscard]] constexpr std::optional<std::string_view> enum_name(E value) noexcept {
+  using D = std::decay_t<E>;
+  const auto name = detail::name_impl<D>(static_cast<int>(value));
 
   if (name.empty()) {
     return std::nullopt;
   } else {
-    return name; // Enum value does not have name.
+    return name; // Enum value does not have name or out of range.
   }
 }
 
-// enum_from_string(name) obtains enum value from enum string name.
-template <typename E, typename = std::enable_if_t<std::is_enum_v<E>>>
-[[nodiscard]] constexpr std::optional<E> enum_from_string(std::string_view name) noexcept {
-  using U = std::underlying_type_t<E>;
-  using C = std::common_type_t<int, U>;
-  constexpr int min = std::max<C>(std::is_signed_v<U> ? -MAGIC_ENUM_RANGE : 0, std::numeric_limits<U>::min());
-  constexpr int max = std::min<C>(MAGIC_ENUM_RANGE, std::numeric_limits<U>::max());
-  constexpr int range = max - min + 1;
+// Obtains string enum name sequence.
+template <typename E, typename = detail::enable_if_enum_t<E>>
+[[nodiscard]] constexpr decltype(auto) enum_names() noexcept {
+  using D = std::decay_t<E>;
+  constexpr auto count = detail::values_impl<D>(detail::enum_range<D>::sequence).size();
+  constexpr auto names = detail::names_impl<D>(std::make_index_sequence<count>{});
 
-  return detail::enum_from_string_impl<E, min>(name, std::make_integer_sequence<int, range>{});
+  return names;
 }
 
-// enum_to_sequence<enum>() obtains value enum sequence.
-template <typename E, typename = std::enable_if_t<std::is_enum_v<E>>>
-[[nodiscard]] constexpr decltype(auto) enum_to_sequence() noexcept {
-  using U = std::underlying_type_t<E>;
-  using C = std::common_type_t<int, U>;
-  constexpr int min = std::max<C>(std::is_signed_v<U> ? -MAGIC_ENUM_RANGE : 0, std::numeric_limits<U>::min());
-  constexpr int max = std::min<C>(MAGIC_ENUM_RANGE, std::numeric_limits<U>::max());
-  constexpr int range = max - min + 1;
+namespace ops {
 
-  return detail::enum_to_sequence_impl<E, min>(std::make_integer_sequence<int, range>{});
+template <typename E, typename = detail::enable_if_enum_t<E>>
+std::ostream& operator<<(std::ostream& os, E value) {
+  using D = std::decay_t<E>;
+  const auto name = detail::name_impl<D>(static_cast<int>(value));
+
+  if (!name.empty()) {
+    os << name;
+  }
+
+  return os;
 }
 
-// enum_to_string_sequence<enum>() obtains string enum name sequence.
-template <typename E, typename = std::enable_if_t<std::is_enum_v<E>>>
-[[nodiscard]] constexpr decltype(auto) enum_to_string_sequence() noexcept {
-  using U = std::underlying_type_t<E>;
-  using C = std::common_type_t<int, U>;
-  constexpr int min = std::max<C>(std::is_signed_v<U> ? -MAGIC_ENUM_RANGE : 0, std::numeric_limits<U>::min());
-  constexpr int max = std::min<C>(MAGIC_ENUM_RANGE, std::numeric_limits<U>::max());
-  constexpr int range = max - min + 1;
+template <typename E, typename = detail::enable_if_enum_t<E>>
+std::ostream& operator<<(std::ostream& os, std::optional<E> value) {
+  using D = std::decay_t<E>;
 
-  return detail::enum_to_string_sequence_impl<E, min>(std::make_integer_sequence<int, range>{});
+  if (value.has_value()) {
+    const auto name = detail::name_impl<D>(static_cast<int>(value.value()));
+    if (!name.empty()) {
+      os << name;
+    }
+  }
+
+  return os;
 }
 
+} // namespace magic_enum::ops
+
 } // namespace magic_enum

test/test.cpp

@@ -27,6 +27,8 @@
 #include <magic_enum.hpp>
 
 #include <array>
+#include <string>
+#include <sstream>
 
 enum class Color { RED = -12, GREEN = 7, BLUE = 15 };
 
@@ -36,117 +38,195 @@ enum Directions { Up = 85, Down = -42, Right = 119, Left = -119 };
 
 enum number : unsigned long { one = 10, two = 20, three = 30 };
 
-TEST_CASE("magic_enum::enum_to_string(enum)") {
-  Color cr = Color::RED;
-  Color cm[3] = {Color::RED, Color::GREEN, Color::BLUE};
-  REQUIRE(magic_enum::enum_to_string(cr).value() == "RED");
-  REQUIRE(magic_enum::enum_to_string(Color::BLUE).value() == "BLUE");
-  REQUIRE(magic_enum::enum_to_string(cm[1]).value() == "GREEN");
-  REQUIRE_FALSE(magic_enum::enum_to_string(static_cast<Color>(MAGIC_ENUM_RANGE)).has_value());
-  REQUIRE_FALSE(magic_enum::enum_to_string(static_cast<Color>(-MAGIC_ENUM_RANGE)).has_value());
+TEST_CASE("enum_cast") {
+  SECTION("string") {
+#if defined(_MSC_VER) && _MSC_VER < 1920
+#  define constexpr // Visual Studio 2017 have bug with string_view constexpr compare.
+#endif
 
-  Numbers no = Numbers::one;
-  REQUIRE(magic_enum::enum_to_string(no).value() == "one");
-  REQUIRE(magic_enum::enum_to_string(Numbers::two).value() == "two");
-  REQUIRE(magic_enum::enum_to_string(Numbers::three).value() == "three");
-  REQUIRE_FALSE(magic_enum::enum_to_string(static_cast<Numbers>(MAGIC_ENUM_RANGE)).has_value());
-  REQUIRE_FALSE(magic_enum::enum_to_string(static_cast<Numbers>(-MAGIC_ENUM_RANGE)).has_value());
+    constexpr auto cr = magic_enum::enum_cast<Color>("RED");
+    REQUIRE(cr.value() == Color::RED);
+    REQUIRE(magic_enum::enum_cast<Color>("GREEN").value() == Color::GREEN);
+    REQUIRE(magic_enum::enum_cast<Color>("BLUE").value() == Color::BLUE);
+    REQUIRE_FALSE(magic_enum::enum_cast<Color>("None").has_value());
 
-  Directions dr = Directions::Right;
-  REQUIRE(magic_enum::enum_to_string(Directions::Up).value() == "Up");
-  REQUIRE(magic_enum::enum_to_string(Directions::Down).value() == "Down");
-  REQUIRE(magic_enum::enum_to_string(dr).value() == "Right");
-  REQUIRE(magic_enum::enum_to_string(Directions::Left).value() == "Left");
-  REQUIRE_FALSE(magic_enum::enum_to_string(static_cast<Directions>(MAGIC_ENUM_RANGE)).has_value());
-  REQUIRE_FALSE(magic_enum::enum_to_string(static_cast<Directions>(-MAGIC_ENUM_RANGE)).has_value());
+    constexpr auto no = magic_enum::enum_cast<Numbers>("one");
+    REQUIRE(no.value() == Numbers::one);
+    REQUIRE(magic_enum::enum_cast<Numbers>("two").value() == Numbers::two);
+    REQUIRE(magic_enum::enum_cast<Numbers>("three").value() == Numbers::three);
+    REQUIRE_FALSE(magic_enum::enum_cast<Numbers>("None").has_value());
 
-  number nt = number::three;
-  REQUIRE(magic_enum::enum_to_string(number::one).value() == "one");
-  REQUIRE(magic_enum::enum_to_string(number::two).value() == "two");
-  REQUIRE(magic_enum::enum_to_string(nt).value() == "three");
-  REQUIRE_FALSE(magic_enum::enum_to_string(static_cast<number>(MAGIC_ENUM_RANGE)).has_value());
-  REQUIRE_FALSE(magic_enum::enum_to_string(static_cast<number>(-MAGIC_ENUM_RANGE)).has_value());
+    constexpr auto dr = magic_enum::enum_cast<Directions>("Right");
+    REQUIRE(magic_enum::enum_cast<Directions>("Up").value() == Directions::Up);
+    REQUIRE(magic_enum::enum_cast<Directions>("Down").value() == Directions::Down);
+    REQUIRE(dr.value() == Directions::Right);
+    REQUIRE(magic_enum::enum_cast<Directions>("Left").value() == Directions::Left);
+    REQUIRE_FALSE(magic_enum::enum_cast<Directions>("None").has_value());
+
+    constexpr auto nt = magic_enum::enum_cast<number>("three");
+    REQUIRE(magic_enum::enum_cast<number>("one").value() == number::one);
+    REQUIRE(magic_enum::enum_cast<number>("two").value() == number::two);
+    REQUIRE(nt.value() == number::three);
+    REQUIRE_FALSE(magic_enum::enum_cast<number>("None").has_value());
+
+#undef constexpr
+  }
+
+  SECTION("string") {
+    constexpr auto cr = magic_enum::enum_cast<Color>(-12);
+    REQUIRE(cr.value() == Color::RED);
+    REQUIRE(magic_enum::enum_cast<Color>(7).value() == Color::GREEN);
+    REQUIRE(magic_enum::enum_cast<Color>(15).value() == Color::BLUE);
+    REQUIRE_FALSE(magic_enum::enum_cast<Color>(0).has_value());
+
+    constexpr auto no = magic_enum::enum_cast<Numbers>(10);
+    REQUIRE(no.value() == Numbers::one);
+    REQUIRE(magic_enum::enum_cast<Numbers>(20).value() == Numbers::two);
+    REQUIRE(magic_enum::enum_cast<Numbers>(30).value() == Numbers::three);
+    REQUIRE_FALSE(magic_enum::enum_cast<Numbers>(0).has_value());
+
+    constexpr auto dr = magic_enum::enum_cast<Directions>(119);
+    REQUIRE(magic_enum::enum_cast<Directions>(85).value() == Directions::Up);
+    REQUIRE(magic_enum::enum_cast<Directions>(-42).value() == Directions::Down);
+    REQUIRE(dr.value() == Directions::Right);
+    REQUIRE(magic_enum::enum_cast<Directions>(-119).value() == Directions::Left);
+    REQUIRE_FALSE(magic_enum::enum_cast<Directions>(0).has_value());
+
+    constexpr auto nt = magic_enum::enum_cast<number>(30);
+    REQUIRE(magic_enum::enum_cast<number>(10).value() == number::one);
+    REQUIRE(magic_enum::enum_cast<number>(20).value() == number::two);
+    REQUIRE(nt.value() == number::three);
+    REQUIRE_FALSE(magic_enum::enum_cast<number>(0).has_value());
+  }
 }
 
-TEST_CASE("magic_enum::enum_to_string<enum>()") {
-  constexpr Color cr = Color::RED;
-  constexpr Color cm[3] = {Color::RED, Color::GREEN, Color::BLUE};
-  REQUIRE(magic_enum::enum_to_string<cr>().value() == "RED");
-  REQUIRE(magic_enum::enum_to_string<Color::BLUE>().value() == "BLUE");
-  REQUIRE(magic_enum::enum_to_string<cm[1]>().value() == "GREEN");
-  REQUIRE_FALSE(magic_enum::enum_to_string<static_cast<Color>(MAGIC_ENUM_RANGE)>().has_value());
-  REQUIRE_FALSE(magic_enum::enum_to_string<static_cast<Color>(-MAGIC_ENUM_RANGE)>().has_value());
+TEST_CASE("enum_value") {
+ constexpr auto cr = magic_enum::enum_value<Color>(0);
+  REQUIRE(cr == Color::RED);
+  REQUIRE(magic_enum::enum_value<Color>(1) == Color::GREEN);
+  REQUIRE(magic_enum::enum_value<Color>(2) == Color::BLUE);
 
-  constexpr Numbers no = Numbers::one;
-  REQUIRE(magic_enum::enum_to_string<no>().value() == "one");
-  REQUIRE(magic_enum::enum_to_string<Numbers::two>().value() == "two");
-  REQUIRE(magic_enum::enum_to_string<Numbers::three>().value() == "three");
-  REQUIRE_FALSE(magic_enum::enum_to_string<static_cast<Numbers>(MAGIC_ENUM_RANGE)>().has_value());
-  REQUIRE_FALSE(magic_enum::enum_to_string<static_cast<Numbers>(-MAGIC_ENUM_RANGE)>().has_value());
+  constexpr auto no = magic_enum::enum_value<Numbers>(0);
+  REQUIRE(no == Numbers::one);
+  REQUIRE(magic_enum::enum_value<Numbers>(1) == Numbers::two);
+  REQUIRE(magic_enum::enum_value<Numbers>(2) == Numbers::three);
 
-  constexpr Directions dr = Directions::Right;
-  REQUIRE(magic_enum::enum_to_string<Directions::Up>().value() == "Up");
-  REQUIRE(magic_enum::enum_to_string<Directions::Down>().value() == "Down");
-  REQUIRE(magic_enum::enum_to_string<dr>().value() == "Right");
-  REQUIRE(magic_enum::enum_to_string<Directions::Left>().value() == "Left");
-  REQUIRE_FALSE(magic_enum::enum_to_string<static_cast<Directions>(MAGIC_ENUM_RANGE)>().has_value());
-  REQUIRE_FALSE(magic_enum::enum_to_string<static_cast<Directions>(-MAGIC_ENUM_RANGE)>().has_value());
+  constexpr auto dr = magic_enum::enum_value<Directions>(3);
+  REQUIRE(magic_enum::enum_value<Directions>(0) == Directions::Left);
+  REQUIRE(magic_enum::enum_value<Directions>(1) == Directions::Down);
+  REQUIRE(magic_enum::enum_value<Directions>(2) == Directions::Up);
+  REQUIRE(dr == Directions::Right);
 
-  constexpr number nt = number::three;
-  REQUIRE(magic_enum::enum_to_string<number::one>().value() == "one");
-  REQUIRE(magic_enum::enum_to_string<number::two>().value() == "two");
-  REQUIRE(magic_enum::enum_to_string<nt>().value() == "three");
-  REQUIRE_FALSE(magic_enum::enum_to_string<static_cast<number>(MAGIC_ENUM_RANGE)>().has_value());
-  REQUIRE_FALSE(magic_enum::enum_to_string<static_cast<number>(-MAGIC_ENUM_RANGE)>().has_value());
+  constexpr auto nt = magic_enum::enum_value<number>(2);
+  REQUIRE(magic_enum::enum_value<number>(0) == number::one);
+  REQUIRE(magic_enum::enum_value<number>(1) == number::two);
+  REQUIRE(nt == number::three);
 }
 
-TEST_CASE("magic_enum::enum_from_string(name)") {
-  REQUIRE(magic_enum::enum_from_string<Color>("RED").value() == Color::RED);
-  REQUIRE(magic_enum::enum_from_string<Color>("GREEN").value() == Color::GREEN);
-  REQUIRE(magic_enum::enum_from_string<Color>("BLUE").value() == Color::BLUE);
-  REQUIRE_FALSE(magic_enum::enum_from_string<Color>("None").has_value());
-
-  REQUIRE(magic_enum::enum_from_string<Numbers>("one").value() == Numbers::one);
-  REQUIRE(magic_enum::enum_from_string<Numbers>("two").value() == Numbers::two);
-  REQUIRE(magic_enum::enum_from_string<Numbers>("three").value() == Numbers::three);
-  REQUIRE_FALSE(magic_enum::enum_from_string<Numbers>("None").has_value());
-
-  REQUIRE(magic_enum::enum_from_string<Directions>("Up").value() == Directions::Up);
-  REQUIRE(magic_enum::enum_from_string<Directions>("Down").value() == Directions::Down);
-  REQUIRE(magic_enum::enum_from_string<Directions>("Right").value() == Directions::Right);
-  REQUIRE(magic_enum::enum_from_string<Directions>("Left").value() == Directions::Left);
-  REQUIRE_FALSE(magic_enum::enum_from_string<Directions>("None").has_value());
-
-  REQUIRE(magic_enum::enum_from_string<number>("one").value() == number::one);
-  REQUIRE(magic_enum::enum_from_string<number>("two").value() == number::two);
-  REQUIRE(magic_enum::enum_from_string<number>("three").value() == number::three);
-  REQUIRE_FALSE(magic_enum::enum_from_string<number>("None").has_value());
-}
-
-TEST_CASE("magic_enum::enum_sequence<enum>()") {
-  constexpr auto mge_s1 = magic_enum::enum_to_sequence<Color>();
+TEST_CASE("enum_values") {
+  constexpr auto mge_s1 = magic_enum::enum_values<Color>();
   REQUIRE(mge_s1 == std::array<Color, 3>{Color::RED, Color::GREEN, Color::BLUE});
 
-  constexpr auto mge_s2 = magic_enum::enum_to_sequence<Numbers>();
+  constexpr auto mge_s2 = magic_enum::enum_values<Numbers>();
   REQUIRE(mge_s2 == std::array<Numbers, 3>{Numbers::one, Numbers::two, Numbers::three});
 
-  constexpr auto mge_s3 = magic_enum::enum_to_sequence<Directions>();
+  constexpr auto mge_s3 = magic_enum::enum_values<Directions>();
   REQUIRE(mge_s3 == std::array<Directions, 4>{Directions::Left, Directions::Down, Directions::Up, Directions::Right});
 
-  constexpr auto mge_s4 = magic_enum::enum_to_sequence<number>();
+  constexpr auto mge_s4 = magic_enum::enum_values<number>();
   REQUIRE(mge_s4 == std::array<number, 3>{number::one, number::two, number::three});
 }
 
-TEST_CASE("magic_enum::enum_to_string_sequence<enum>()") {
-  constexpr auto mge_s1 = magic_enum::enum_to_string_sequence<Color>();
+TEST_CASE("enum_count") {
+  constexpr auto mge_s1 = magic_enum::enum_count<Color>();
+  REQUIRE(mge_s1 == 3);
+
+  constexpr auto mge_s2 = magic_enum::enum_count<Numbers>();
+  REQUIRE(mge_s2 == 3);
+
+  constexpr auto mge_s3 = magic_enum::enum_count<Directions>();
+  REQUIRE(mge_s3 == 4);
+
+  constexpr auto mge_s4 = magic_enum::enum_count<number>();
+  REQUIRE(mge_s4 == 3);
+}
+
+TEST_CASE("enum_name") {
+  constexpr Color cr = Color::RED;
+  constexpr auto cr_name = magic_enum::enum_name(cr);
+  Color cm[3] = {Color::RED, Color::GREEN, Color::BLUE};
+  REQUIRE(cr_name.value() == "RED");
+  REQUIRE(magic_enum::enum_name(Color::BLUE).value() == "BLUE");
+  REQUIRE(magic_enum::enum_name(cm[1]).value() == "GREEN");
+  REQUIRE_FALSE(magic_enum::enum_name(static_cast<Color>(MAGIC_ENUM_RANGE)).has_value());
+  REQUIRE_FALSE(magic_enum::enum_name(static_cast<Color>(-MAGIC_ENUM_RANGE)).has_value());
+
+  constexpr Numbers no = Numbers::one;
+  constexpr auto no_name = magic_enum::enum_name(no);
+  REQUIRE(no_name.value() == "one");
+  REQUIRE(magic_enum::enum_name(Numbers::two).value() == "two");
+  REQUIRE(magic_enum::enum_name(Numbers::three).value() == "three");
+  REQUIRE_FALSE(magic_enum::enum_name(static_cast<Numbers>(MAGIC_ENUM_RANGE)).has_value());
+  REQUIRE_FALSE(magic_enum::enum_name(static_cast<Numbers>(-MAGIC_ENUM_RANGE)).has_value());
+
+  constexpr Directions dr = Directions::Right;
+  constexpr auto dr_name = magic_enum::enum_name(dr);
+  REQUIRE(magic_enum::enum_name(Directions::Up).value() == "Up");
+  REQUIRE(magic_enum::enum_name(Directions::Down).value() == "Down");
+  REQUIRE(dr_name.value() == "Right");
+  REQUIRE(magic_enum::enum_name(Directions::Left).value() == "Left");
+  REQUIRE_FALSE(magic_enum::enum_name(static_cast<Directions>(MAGIC_ENUM_RANGE)).has_value());
+  REQUIRE_FALSE(magic_enum::enum_name(static_cast<Directions>(-MAGIC_ENUM_RANGE)).has_value());
+
+  constexpr number nt = number::three;
+  constexpr auto nt_name = magic_enum::enum_name(nt);
+  REQUIRE(magic_enum::enum_name(number::one).value() == "one");
+  REQUIRE(magic_enum::enum_name(number::two).value() == "two");
+  REQUIRE(nt_name.value() == "three");
+  REQUIRE_FALSE(magic_enum::enum_name(static_cast<number>(MAGIC_ENUM_RANGE)).has_value());
+  REQUIRE_FALSE(magic_enum::enum_name(static_cast<number>(-MAGIC_ENUM_RANGE)).has_value());
+}
+
+TEST_CASE("enum_names") {
+  constexpr auto mge_s1 = magic_enum::enum_names<Color>();
   REQUIRE(mge_s1 == std::array<std::string_view, 3>{"RED", "GREEN", "BLUE"});
 
-  constexpr auto mge_s2 = magic_enum::enum_to_string_sequence<Numbers>();
+  constexpr auto mge_s2 = magic_enum::enum_names<Numbers>();
   REQUIRE(mge_s2 == std::array<std::string_view, 3>{"one", "two", "three"});
 
-  constexpr auto mge_s3 = magic_enum::enum_to_string_sequence<Directions>();
+  constexpr auto mge_s3 = magic_enum::enum_names<Directions>();
   REQUIRE(mge_s3 == std::array<std::string_view, 4>{"Left", "Down", "Up", "Right"});
 
-  constexpr auto mge_s4 = magic_enum::enum_to_string_sequence<number>();
+  constexpr auto mge_s4 = magic_enum::enum_names<number>();
   REQUIRE(mge_s4 == std::array<std::string_view, 3>{"one", "two", "three"});
 }
+
+TEST_CASE("operator<<") {
+  auto test_ostream = [](auto e, std::string_view name) {
+    using namespace magic_enum::ops;
+    std::stringstream ss;
+    ss << e;
+    REQUIRE(ss.str() == name);
+  };
+
+  test_ostream(Color::RED, "RED");
+  test_ostream(Color::GREEN, "GREEN");
+  test_ostream(Color::BLUE, "BLUE");
+  test_ostream((Color)0, "");
+
+  test_ostream(Numbers::one, "one");
+  test_ostream(Numbers::two, "two");
+  test_ostream(Numbers::three, "three");
+  test_ostream((Numbers)0, "");
+
+  test_ostream(Directions::Up, "Up");
+  test_ostream(Directions::Down, "Down");
+  test_ostream(Directions::Right, "Right");
+  test_ostream(Directions::Left, "Left");
+  test_ostream((Directions)0, "");
+
+  test_ostream(number::one, "one");
+  test_ostream(number::two, "two");
+  test_ostream(number::three, "three");
+  test_ostream((number)0, "");
+}