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title: "noreturn | Microsoft Docs"
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---
# noreturn
## Microsoft Specific  
 This `__declspec` attribute tells the compiler that a function does not return. As a consequence, the compiler knows that the code following a call to a **__declspec(noreturn)** function is unreachable.  
  
 If the compiler finds a function with a control path that does not return a value, it generates a warning (C4715) or error message (C2202). If the control path cannot be reached due to a function that never returns, you can use **__declspec(noreturn)** to prevent this warning or error.  
  
> [!NOTE]
>  Adding **__declspec(noreturn)** to a function that is expected to return can result in undefined behavior.  
  
## Example  
 In the following sample,the **else** clause does not contain a return statement.  Declaring `fatal` as **__declspec(noreturn)** avoids an error or warning message.  
  
```  
// noreturn2.cpp  
__declspec(noreturn) extern void fatal () {}  
  
int main() {  
   if(1)  
     return 1;  
   else if(0)  
     return 0;  
   else  
     fatal();  
}  
```  
  
## See Also  
 [__declspec](../cpp/declspec.md)   
 [Keywords](../cpp/keywords-cpp.md)