Can I tell the compiler to consider a control path closed with regards to return value?

Question

Say I have the following function: ``` Thingy& getThingy(int id) { for ( int i = 0; i < something(); ++i ) { // normal execution guarantees that the Thingy we're looking for exists if ( thingyArray[i].id == id ) return thingyArray[i]; } // If we got this far, then something went horribly wrong and we can't recover. // This function terminates the program. fatalError("The sky is falling!"); // Execution will never reach this point. } ``` Compilers will typically complain at this, saying that "not all control paths return a value". Which is technically true, but the control paths that don't return a value abort the program before the function ends, and are therefore semantically correct. Is there a way to tell the compiler (VS2010 in my case, but I'm curious about others as well) that a certain control path is to be ignored for the purposes of this check, without suppressing the warning completely or returning a nonsensical dummy value at the end of the function?

Accepted Answer

You can annotate the function `fatalError` (its declaration) to let the compiler know it will never return.

In C++11, this would be something like:

```
[[noreturn]] void fatalError(std::string const&);
```

Pre C++11, you have compiler specific attributes, such as GCC's:

```
void fatalError(std::string const&) __attribute__((noreturn));
```

or Visual Studio's:

```
__declspec(noreturn) void fatalError(std::string const&);
```

Can I tell the compiler to consider a control path closed with regards to return value?

Solution

Problem