Re: [Boost-users] boost::bind issues revisited

Subject: Re: [Boost-users] boost::bind issues revisited
From: Littlefield, Tyler (tyler_at_[hidden])
Date: 2013-04-22 10:29:56

On 4/22/2013 1:07 AM, Nathan Ridge wrote:
> ----------------------------------------
>> Date: Mon, 22 Apr 2013 00:52:27 -0600
>> From: tyler_at_[hidden]
>> To: boost-users_at_[hidden]
>> Subject: [Boost-users] boost::bind issues revisited
>>
>> Hello all:
>> I'm kind of at a loss here. It looks like ther'es an issue with
>> boost::bind somewhere in the mess of 500 templates and 90 screens of
>> errors and I don't know enough about the mess to untangle it. Any info
>> would be awesome. First, the code:
>>
>> sgroup->AddEntry(new OlcStringEntry("name", "Sets the name of the
>> object", OF_NORMAL,
>> boost::bind(&StaticObject::GetName, _1),
>> <159> boost::bind(&StaticObject::SetName, _1, _2)));
>>
>> the 159 I denoted is useful in the errors later.
>> Now the rest of the code I'm using:
>>
>> typedef boost::function<std::string ()> StringGetter;
>> typedef boost::function<void (const std::string&)> StringSetter;
>>
>> class IOlcEntry
>> {
>> protected:
>> std::string _name;
>> std::string _help;
>> FLAG _flag;
>> public:
>> IOlcEntry(const std::string &name, const std::string &help, FLAG flag)
>> {
>> _flag = flag;
>> _name = name;
>> _help = help;
>> }
>> ~IOlcEntry() {}
>> };
>>
>> class OlcStringEntry:public IOlcEntry
>> {
>> protected:
>> StringGetter _getter;
>> StringSetter _setter;
>> public:
>> OlcStringEntry(const std::string &name, const std::string &help, FLAG
>> flag, const StringGetter getter, const StringSetter setter)
>> :IOlcEntry(name, help, flag)
>> {
>> _setter = setter;
>> _getter = getter;
>> }
>> };
> Looks like you are trying to pass "boost::bind(&StaticObject::GetName, _1)",
> which is a 1-argument function object, as the argument for a parameter of
> type "StringGetter", which is a typedef for "boost::function<std::string ()>",
> which is a 0-argument function object.
>
> You have a similar problem for the setter.
>
> Perhaps you meant to bind the getter and setter to a specific instance of
> StaticObject? In that case, assuming 'my_instance' is that instance, you
> should write:
>
> boost::bind(&StaticObject::GetName, my_instance)
>
> and
>
> boost::bind(&StaticObject::SetName, my_instance, _1)
>
> and then you'll have function objects that are assignable to StringGetter
> and StringSetter, respectively.
>
> Regards,
> Nate 		 	   		
>
Hello:
I should have been more clear in my original message. Basically what I'm 
doing is creating a method that I can use to edit objects in game. 
Rather than attach this to every object, the idea was to set up a 
collection of editor entries. When I wanted to edit an object I can call 
these entries on the object. This saves a lot of overhead because rather 
than there being x*n (where n is the amount of objects) entries, there's 
just x and each object can call into them when it is edited. I was 
trying to use _1 etc as placeholders for the "this" pointer; is it 
possible to do that? I'd like to be able to use any StaticObject I wish 
with these entries, but I need a way to pass in the this pointer for the 
object.
Thanks,