Two functions having same body different name

Question

Is it possible to have two functions with the different function name but the same functionality share the function body? And how can we do it?

template<typename _T>
class array {
public:
    _T operator+(_T concatinate_operand); // concatinate to the array
    _T append(_T concatinate_operand);
};

But you need different `+` operator overload semantic. I.e. something like `array& operator+(const array& rhs) { append(rhs.data_,rsh.length_); return *this; };` — Victor Gubin, Jun 13 '18 at 19:11
Utterly and totally unrelated: Show a wee bit of fear any time you precede an upper case letter with an underscore. For why, read [What are the rules about using an underscore in a C++ identifier?](https://stackoverflow.com/questions/228783/what-are-the-rules-about-using-an-underscore-in-a-c-identifier) — user4581301, Jun 13 '18 at 19:42

NathanOliver · Accepted Answer · 2018-06-13T19:09:37.850

5

Yes, this is quite easy to accomplish. You just call the function the you do the actual implementation in from the other one. That would look like

template<typename _T>
class array {
public:
    _T operator+(_T concatinate_operand) { return append(concatinate_operand); } // concatinate to the array
    _T append(_T concatinate_operand) { /*actual logic here*/ }
};

Do note that if T is large then passing it by value and getting a copy will hurt the performance. If you use references like

template<typename _T>
class array {
public:
    _T& operator+(const _T& concatinate_operand) { return append(concatinate_operand); } // concatinate to the array
    _T& append(const _T& concatinate_operand) { /*actual logic here*/ }
};

You will avoid unnecessary copies.

edited Jun 13 '18 at 19:09

answered Jun 13 '18 at 18:56

NathanOliver

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It would be odd for `operator+` to return a `T&`. Or maybe the oddity is that `operator+` and `append` are expected to do the same thing. – François Andrieux Jun 13 '18 at 19:20
`_T& operator+(const _T& concatinate_operand)` is actually bad idea :) `char * foo = nullptr; if(some) { array arr("abcd",5); foo = arr + "12345"; } delete [] foo;` – Victor Gubin Jun 13 '18 at 19:20
@VictorGubin What is that code suppose to be/do? It wouldn't compile and it seems to be trying to do terrible things. – François Andrieux Jun 13 '18 at 19:21
@VictorGubin That code won't work in the first place. – NathanOliver Jun 13 '18 at 19:21
@NathanOliver Exactly like member operator `+` returning reference on member pointer. And `foo = arr + "12345"` may work if not `template<> array { explicit array(const char* cstr) {} ` – Victor Gubin Jun 13 '18 at 19:27
1

@VictorGubin I'm sorry but I don't understand the point you are trying to make. – NathanOliver Jun 13 '18 at 19:29
@NathanOliver Check operator '+' result type, it returns reference on on template parameter type, when it should return reference on array class type. i.e. something like `array c = array("abcd",5) + array("fig",4);` – Victor Gubin Jun 13 '18 at 19:34
1

@VictorGubin Why? That is not what the OP has. It looks like the want to use `+` or `append` to add an element to the end of the array. – NathanOliver Jun 13 '18 at 19:36

Two functions having same body different name

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