build: remove entt library

include/entt/core/monostate.hpp

@@ -1,60 +0,0 @@
-#ifndef ENTT_CORE_MONOSTATE_HPP
-#define ENTT_CORE_MONOSTATE_HPP
-
-#include "../config/config.h"
-#include "fwd.hpp"
-
-namespace entt {
-
-/**
- * @brief Minimal implementation of the monostate pattern.
- *
- * A minimal, yet complete configuration system built on top of the monostate
- * pattern. Thread safe by design, it works only with basic types like `int`s or
- * `bool`s.<br/>
- * Multiple types and therefore more than one value can be associated with a
- * single key. Because of this, users must pay attention to use the same type
- * both during an assignment and when they try to read back their data.
- * Otherwise, they can incur in unexpected results.
- */
-template<id_type>
-struct monostate {
-    /**
-     * @brief Assigns a value of a specific type to a given key.
-     * @tparam Type Type of the value to assign.
-     * @param val User data to assign to the given key.
-     * @return This monostate object.
-     */
-    template<typename Type>
-    monostate &operator=(Type val) noexcept {
-        value<Type> = val;
-        return *this;
-    }
-
-    /**
-     * @brief Gets a value of a specific type for a given key.
-     * @tparam Type Type of the value to get.
-     * @return Stored value, if any.
-     */
-    template<typename Type>
-    operator Type() const noexcept {
-        return value<Type>;
-    }
-
-private:
-    template<typename Type>
-    // NOLINTNEXTLINE(cppcoreguidelines-avoid-non-const-global-variables)
-    inline static ENTT_MAYBE_ATOMIC(Type) value{};
-};
-
-/**
- * @brief Helper variable template.
- * @tparam Value Value used to differentiate between different variables.
- */
-template<id_type Value>
-// NOLINTNEXTLINE(cppcoreguidelines-avoid-non-const-global-variables)
-inline monostate<Value> monostate_v{};
-
-} // namespace entt
-
-#endif