signal if wrong type of getJsonValue() in compile-time

lubynets · lubynets · commit c40c3d6f47b0 · 2025-12-24T22:36:26.000+01:00
diff --git a/PWGHF/D2H/Macros/runMassFitter.C b/PWGHF/D2H/Macros/runMassFitter.C
@@ -575,6 +575,9 @@ T* getObjectWithNullPtrCheck(TFile* fileIn, const std::string& objectName)
   return ptr;
 }
 
+template <typename>
+constexpr bool AlwaysFalse = false;
+
 template <typename T>
 T getJsonValue(const Value& value)
 {
@@ -586,9 +589,10 @@ T getJsonValue(const Value& value)
     return value.GetInt();
   } else if constexpr (std::is_same_v<std::decay_t<T>, double>) {
     return value.GetDouble();
+  } else {
+    static_assert(AlwaysFalse<T>, "getJsonValue(): unsupported type!");
+    return T();
   }
-  throw std::runtime_error("getJsonValue(): unsupported type!");
-  return T();
 }
 
 template <typename T>

Original file line number	Diff line number	Diff line change
`@@ -575,6 +575,9 @@ T* getObjectWithNullPtrCheck(TFile* fileIn, const std::string& objectName)`
`575`	`575`	`return ptr;`
`576`	`576`	`}`
`577`	`577`
	`578`	`+template <typename>`
	`579`	`+constexpr bool AlwaysFalse = false;`
	`580`	`+`
`578`	`581`	`template <typename T>`
`579`	`582`	`T getJsonValue(const Value& value)`
`580`	`583`	`{`
`@@ -586,9 +589,10 @@ T getJsonValue(const Value& value)`
`586`	`589`	`return value.GetInt();`
`587`	`590`	`} else if constexpr (std::is_same_v<std::decay_t<T>, double>) {`
`588`	`591`	`return value.GetDouble();`
	`592`	`+ } else {`
	`593`	`+ static_assert(AlwaysFalse<T>, "getJsonValue(): unsupported type!");`
	`594`	`+ return T();`
`589`	`595`	`}`
`590`		`- throw std::runtime_error("getJsonValue(): unsupported type!");`
`591`		`- return T();`
`592`	`596`	`}`
`593`	`597`
`594`	`598`	`template <typename T>`