maths: make round_pow2 constexpr

maths.cpp

@@ -52,33 +52,6 @@ template uint32_t util::log2 (uint32_t);
 template uint64_t util::log2 (uint64_t);
 
 
-///////////////////////////////////////////////////////////////////////////////
-template <typename T>
-std::enable_if_t<
-    std::is_integral<T>::value, T
->
-util::round_pow2 (T value)
-{
-    using return_type = std::enable_if_t<std::is_integral<T>::value, T>;
-
-    --value;
-
-    for (unsigned i = 1; i < sizeof (T) * 8; i <<= 1) {
-        value |= value >> i;
-    }
-
-    ++value;
-    return (return_type)value;
-}
-
-
-//-----------------------------------------------------------------------------
-template uint8_t  util::round_pow2 (uint8_t);
-template uint16_t util::round_pow2 (uint16_t);
-template uint32_t util::round_pow2 (uint32_t);
-template uint64_t util::round_pow2 (uint64_t);
-
-
 ///////////////////////////////////////////////////////////////////////////////
 template const float  util::PI<float>;
 template const double util::PI<double>;

maths.hpp

@@ -245,10 +245,23 @@ namespace util {
 
     //-----------------------------------------------------------------------------
     template <typename T>
+    constexpr
     std::enable_if_t<
         std::is_integral<T>::value, T
     >
-    round_pow2  (T value);
+    round_pow2  (T value)
+    {
+        using return_type = std::enable_if_t<std::is_integral<T>::value, T>;
+
+        --value;
+
+        for (unsigned i = 1; i < sizeof (T) * 8; i <<= 1) {
+            value |= value >> i;
+        }
+
+        ++value;
+        return (return_type)value;
+    }
 
 
     //-----------------------------------------------------------------------------