1 files changed, 54 insertions, 0 deletions
diff --git a/compat/clamp.hpp b/compat/clamp.hpp
new file mode 100644
index 00000000..8141e25f
--- /dev/null
+++ b/compat/clamp.hpp
@@ -0,0 +1,54 @@
+#pragma once
+
+#include <cmath>
+#include <type_traits>
+
+#include "macros.hpp"
+
+namespace util_detail {
+
+template<typename n>
+inline auto clamp_float(n val, n min_, n max_)
+{
+    return std::fmin(std::fmax(val, min_), max_);
+}
+
+template<typename t, typename n>
+struct clamp final
+{
+    static inline auto clamp_(const n& val, const n& min_, const n& max_)
+    {
+        if (unlikely(val > max_))
+            return max_;
+        if (unlikely(val < min_))
+            return min_;
+        return val;
+    }
+};
+
+template<typename t>
+struct clamp<float, t>
+{
+    static inline auto clamp_(float val, float min_, float max_)
+    {
+        return clamp_float(val, min_, max_);
+    }
+};
+
+template<typename t>
+struct clamp<double, t>
+{
+    static inline auto clamp_(double val, double min_, double max_)
+    {
+        return clamp_float(val, min_, max_);
+    }
+};
+
+} // ns util_detail
+
+template<typename t, typename u, typename w>
+inline auto clamp(const t& val, const u& min, const w& max)
+{
+    using tp = decltype(val + min + max);
+    return ::util_detail::clamp<std::decay_t<tp>, tp>::clamp_(val, min, max);
+}