##macro - difference between VC and GC

[toran]

Following code compiles and runs fine in MSVC, but fails in GC. I'll appreciate the help in a)understanding the issue and b)how to make it work for both compilers.

http://codepad.org/hZSQY0QC

class classA 
{
public:
	classA() {}
};

#define PROP(propname) \
	classA& ##propname() {return _##propname;} \
	const classA& const_##propname() {return _##propname;}

class classB
{
public:
	classB() {};
	PROP (prop1);
private:
	classA _prop1;
};


int _tmain(int argc, char* argv[])
{
	classB b;
	return 0;
}

[guestgulkan]

there is a difference in the operation of the ## macro
between GCC and MSVC which can confuse you - but in this case
it should not be an issue.

The macro should look like this:

#define PROP(propname) \
	classA& propname() {return _##propname;} \
	const classA& const_##propname() {return _##propname;} 

[JLBorges]

Why do you want this macro? To save one line of code?

If you must have a macro for this, might as well go the whole hog:

#define DEFINE_PROPERTY( TYPE, NAME ) \
    private: TYPE _property___##NAME ; \
    public : \
        TYPE & NAME() { return _property___##NAME ; } \
        const TYPE & NAME() const { return _property___##NAME ; } \
        const TYPE & const_##NAME() const { return _property___##NAME ; } \
        void NAME( const TYPE& _value___ ) { _property___##NAME = _value___ ; } 

And then:

#include <iostream>
#include <string>

struct A
{
   DEFINE_PROPERTY( int, value ) ;
   DEFINE_PROPERTY( std::string, name ) ;
};

int main()
{
    A a ;
    a.value(99) ;
    a.name("toran") ;
    std::cout << a.value() << ' ' << a.const_name() << '\n' ;
    a.value() += 100 ;
    a.name()[0] = 'T' ;
    std::cout << a.const_value() << ' ' << a.name() << '\n' ;
}