fmt support added

src/include/units/bits/customization_points.h

@@ -0,0 +1,115 @@
+// The MIT License (MIT)
+//
+// Copyright (c) 2018 Mateusz Pusz
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in all
+// copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+// SOFTWARE.
+
+#pragma once
+
+#include <type_traits>
+#include <cmath>
+
+namespace units {
+
+  // treat_as_floating_point
+
+  template<typename Rep>  // TODO Conceptify that
+  inline constexpr bool treat_as_floating_point = std::is_floating_point_v<Rep>;
+
+  // isnan
+  namespace isnan_impl {
+
+    // non-ADL lookup block
+    void isnan(); // undefined
+
+    template<typename>
+    inline constexpr bool has_customization = false;
+
+    template<typename T>
+      requires requires(const T& t) {
+        { isnan(t) } -> bool;
+      }
+    inline constexpr bool has_customization<T> = true;
+
+    struct fn {
+      template<typename T>
+      constexpr bool operator()(const T&) const
+      {
+        return false;
+      }
+
+      template<typename T>
+        requires treat_as_floating_point<T>
+      constexpr bool operator()(const T& value) const
+      {
+        return std::isnan(value);
+      }
+
+      template<typename T>
+        requires treat_as_floating_point<T> && has_customization<T>
+      constexpr bool operator()(const T& value) const
+      {
+        return isnan(value);  // uses ADL
+      }
+    };
+  }
+
+  inline constexpr isnan_impl::fn isnan{};
+
+  // isfinite
+  namespace isfinite_impl {
+
+    // non-ADL lookup block
+    void isfinite(); // undefined
+
+    template<typename>
+    inline constexpr bool has_customization = false;
+
+    template<typename T>
+      requires requires(const T& t) {
+        { isfinite(t) } -> bool;
+      }
+    inline constexpr bool has_customization<T> = true;
+
+    struct fn {
+      template<typename T>
+      constexpr bool operator()(const T&) const
+      {
+        return true;
+      }
+
+      template<typename T>
+        requires treat_as_floating_point<T>
+      constexpr bool operator()(const T& value) const
+      {
+        return std::isfinite(value);
+      }
+
+      template<typename T>
+        requires treat_as_floating_point<T> && has_customization<T>
+      constexpr bool operator()(const T& value) const
+      {
+        return isfinite(value);  // uses ADL
+      }
+    };
+  }
+
+  inline constexpr isfinite_impl::fn isfinite{};
+
+}