Support macOS

This allows building and running under macOS.
There is still some issues with dpi but the application compiles and run now.

include/helpers/utils.hpp

@@ -18,6 +18,33 @@
 
 #include "lang/token.hpp"
 
+#ifdef __APPLE__
+    #define off64_t off_t
+    #define fopen64 fopen
+    #define fseeko64 fseek
+    #define ftello64 ftell
+#endif
+
+#if defined(_LIBCPP_VERSION) && _LIBCPP_VERSION <= 12000
+#if __has_include(<concepts>)
+// Make sure we break when derived_from is implemented in libc++. Then we can fix a compatibility version above
+#include <concepts>
+#endif
+// libcxx 12 still doesn't have derived_from implemented, as a result we need to define it ourself using clang built-ins.
+// [concept.derived] (patch from https://reviews.llvm.org/D74292)
+namespace hex {
+template<class _Dp, class _Bp>
+    concept derived_from =
+      __is_base_of(_Bp, _Dp) && __is_convertible_to(const volatile _Dp*, const volatile _Bp*);
+}
+#else
+// Assume supported
+#include <concepts>
+namespace hex {
+    using std::derived_from;
+}
+#endif
+
 namespace hex {
 
     template<typename ... Args>
@@ -99,6 +126,19 @@ namespace hex {
             throw std::invalid_argument("Invalid value size!");
     }
 
+    template< class T >
+    constexpr T bit_width(T x) noexcept {
+        return std::numeric_limits<T>::digits - std::countl_zero(x);
+    }
+
+    template<typename T>
+    constexpr T bit_ceil(T x) noexcept {
+        if (x <= 1u)
+            return T(1);
+
+        return T(1) << bit_width(T(x - 1));
+    }
+
     std::vector<u8> readFile(std::string_view path);
 
     class ScopeExit {

include/providers/provider.hpp

@@ -3,7 +3,6 @@
 #include <hex.hpp>
 
 #include <cmath>
-#include <concepts>
 #include <map>
 #include <optional>
 #include <string>

include/views/view_pattern.hpp

@@ -7,7 +7,6 @@
 
 #include "providers/provider.hpp"
 
-#include <concepts>
 #include <cstring>
 #include <filesystem>
 

include/window.hpp

@@ -1,10 +1,10 @@
 #pragma once
 
-#include <concepts>
 #include <filesystem>
 #include <memory>
 #include <vector>
 
+#include "helpers/utils.hpp"
 #include "views/view.hpp"
 
 struct GLFWwindow;
@@ -19,7 +19,7 @@ namespace hex {
 
         void loop();
 
-        template<std::derived_from<View> T, typename ... Args>
+        template<derived_from<View> T, typename ... Args>
         T* addView(Args&& ... args) {
             this->m_views.emplace_back(new T(std::forward<Args>(args)...));