Conditional operator differences between C and C++

Question

I read somewhere that the `?:` operator in C is slightly different in C++, that there's some source code that works differently in both languages. Unfortunately, I can't find the text anywhere. Does anyone know what this difference is?

Accepted Answer

The conditional operator in C++ can return an lvalue, whereas C does not allow for similar functionality. Hence, the following is legal in C++:

```
(true ? a : b) = 1;
```

To replicate this in C, you would have to resort to if/else, or deal with references directly:

```
*(true ? &a : &b) = 1;
```

Also in C++, `?:` and `=` operators have equal precedence and group right-to-left, such that:

```
(true ? a = 1 : b = 2);
```

is valid C++ code, but will throw an error in C without parentheses around the last expression:

```
(true ? a = 1 : (b = 2));
```

Conditional operator differences between C and C++

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