make DetID constructors constexpr

Author: shahor02

DataFormats/Detectors/Common/include/DetectorsCommonDataFormats/DetID.h

@@ -98,10 +98,18 @@ class DetID
   static constexpr std::string_view ALL{"all"};   ///< keywork for all detectors
 #endif                                            // GPUCA_GPUCODE_DEVICE
 
-  GPUdi() DetID(ID id) : mID(id)
+  constexpr GPUdi() DetID(ID id) : mID(id)
   {
   }
-  DetID(const char* name);
+
+#ifndef GPUCA_GPUCODE_DEVICE
+  constexpr DetID(const char* name) : mID(nameToID(name, First))
+  {
+    // construct from the name
+    assert(mID < nDetectors);
+  }
+#endif // GPUCA_GPUCODE_DEVICE
+
   GPUdDefault() DetID(const DetID& src) = default;
   GPUdDefault() DetID& operator=(const DetID& src) = default;
   // we need default c-tor only for root persistency, code must use c-tor with argument

DataFormats/Detectors/Common/src/DetID.cxx

@@ -61,14 +61,14 @@ DetID::mask_t DetID::getMask(const std::string_view detList)
   }
   return mask;
 }
-
+/*
 //_______________________________
-DetID::DetID(const char* name) : mID(nameToID(name, First))
+constexpr DetID::DetID(const char* name) : mID(nameToID(name, First))
 {
   // construct from the name
   assert(mID < nDetectors);
 }
-
+*/
 //_______________________________
 std::string DetID::getNames(DetID::mask_t mask, char delimiter)
 {