Return a pointer to class member function

Question

The following Problem drives me nuts, though it doesn't seem very odd:

class Foo;

// This is the location of the first error code
//        ↓
int (Foo::*)(int) getPointer()
{
    return 0;
}

GCC gives me:

error: expected unqualified-id before ')' token
error: expected initializer before 'getPointer'

PS: I compile with -std=c++11

@Slava Totally agree, but it's also nice to understand how it works. — Macmade
– Macmade, Commented Nov 13, 2013 at 19:13
@Slava I cannot, since the return type is dependent of a deduced template parameter and you cannot typedef between 'template<>' and 'getPointer()' — Jakob Riedle
– Jakob Riedle, Commented Nov 13, 2013 at 19:35

Macmade · Accepted Answer · 2013-11-13 19:03:10Z

4

int ( Foo::* ( getPointer() ) )();

That being said, remember you can use typedef. For function pointers, it usually improves the overall readability:

typedef int ( Foo::* TypeName )();

TypeName getPointer();

answered Nov 13, 2013 at 19:03

Macmade

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Comments

Ferenc Deak · Accepted Answer · 2013-11-13 19:02:31Z

0

use a typedef, like:

class Foo;

typedef int (Foo::*POINTER)(int);

POINTER getPointer()
{
    return 0;
}

answered Nov 13, 2013 at 19:02

Ferenc Deak

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It is usually bad idea to use all uppercase identifiers.

It usually depends on the coding standard your company decided to adopt.

to use uppercase identifiers for preprocessor does not seem to be a company coding standard, but used everywhere.

CinCout · Accepted Answer · 2013-11-18 07:44:16Z

0

Looks like you are trying to use function pointers, but not giving a name to it :P

Use this:

int (Foo::*myPointer)(int) getPointer()
{
    return 0;
}

answered Nov 13, 2013 at 19:04

CinCout

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