compat/util: fix conversion from value<t> for clamp

1 files changed, 12 insertions, 2 deletions

diff --git a/compat/util.hpp b/compat/util.hpp
index 20be92a4..abcc9ba2 100644
--- a/compat/util.hpp
+++ b/compat/util.hpp
@@ -23,8 +23,10 @@ void run_in_thread_async(QObject* obj, F&& fun)
     QObject::connect(&src, &QObject::destroyed, obj, std::move(fun), Qt::AutoConnection);
 }
 
-template<typename t, typename u, typename w>
-auto clamp(t val, u min, w max) -> decltype (val * min * max)
+namespace detail {
+
+template<typename t, typename u, typename w, typename n>
+inline auto clamp_(n val, n min, n max) -> n
 {
     if (val > max)
         return max;
@@ -33,6 +35,14 @@ auto clamp(t val, u min, w max) -> decltype (val * min * max)
     return val;
 }
 
+}
+
+template<typename t, typename u, typename w>
+inline auto clamp(const t& val, const u& min, const w& max) -> decltype(val * min * max)
+{
+    return ::detail::clamp_<t, u, w, decltype(val * min * max)>(val, min, max);
+}
+
 namespace detail {
 
 template<typename t>