C++ 11 introduced the 'override' specifier for functions and I find it useful as it makes it explicit that a virtual function is being overridden. However, I can't seem to get it work for a function that has been declared using a typedef.
I understand that 'override' is not a keyword, has it got something to do with that?
The following code illustrates my point:
#include <iostream>
typedef char ReturnsChar();
class Basic
{
public:
virtual char get_a();
virtual ReturnsChar get_z;
};
char Basic::get_a() { return 'a'; }
char Basic::get_z() { return 'z'; }
class Capitalized : public Basic
{
public:
// Can override explicitly if I use the normal definition
char get_a() override;
// Compiles if I use the typedef but not 'override'
ReturnsChar get_z;
// Will not compile, but would like to do this
//ReturnsChar get_z override;
};
char Capitalized::get_a() { return 'A'; }
char Capitalized::get_z() { return 'Z'; }
int main()
{
Basic foo;
Capitalized bar;
std::cout << foo.get_a() << std::endl; // a
std::cout << foo.get_z() << std::endl; // z
std::cout << bar.get_a() << std::endl; // A
std::cout << bar.get_z() << std::endl; // Z
}
I'm using GNU's g++ 8.2.0 and the error it gives me is
error: expected ';' at end of member declaration ReturnsChar get_z override; ^~~~~ ; error: ‘override’ does not name a type; did you mean ‘ctermid’? ReturnsChar get_z override; ^~~~~~~~ ctermid
EDIT: To address the comments, I understand this style is unclear. I am more interested about why this won't compile and what exactly 'override' does (especially because it is not a keyword). As an aside, I feel like typedef-ing functions might be clear in some cases, say:
void (*foo(int x, void (*f)(int)))(int);
That's hard to read, especially if comes up often. I can just typedef that as 'UpdateAddressFunction' and then mentally think of every function of that type as something that 'updates an address'.
