"Programming Principles and Practices" errors

[bl4ckb3rry]

I have a pretty big problem with Chapter 12 of "Programming Principles and Practices". Well, in that chapter he introduces graphics. He uses FLTK, which i have downloaded and installed successfully. However, I have a problem with HIS headers. If you don't remember them :
http://www.stroustrup.com/Programming/Graphics/ - from his site.
It's about "Graph.h".
I cannot compile because I get error :
"error C2955: 'Vector' : use of class template requires template argument list".
I have found some "related" problems on : http://cboard.cprogramming.com/cplusplus-programming/139936-libraries-bjarne-stroustrups-book-wont-work.html , but it doesn't solve my problem.

If you are familiar with that error or have some info connected to it, please let me know.

[andywestken]

Vector should be Vector_ref And there's a vector just below (?) which should also be a Vector_ref

(this looks like someone meant to add the standard no-copy incantation and got it wrong!)

Andy

P.S. I've got it to compile... But there are a number of errors in the code which are a bit disappointing to find in a sample. It looks like someone refactored the source to tidy it up, before making it public, but did not check that it still compiled.

Errors:
- 2 methods which were defined inline in the class and again in the cpp file: Circle's constructior and center() method, both defined in Graph.h/.cpp
- Simple_window base class Window being an ambiguous symbol. (Graph_lib::Window vs Window in FLTK, a typedef of HWND) : I fixed this by (a) commenting out the using namespace in Simple_Windows.h and namespace qualifying all the types (Graph_lib::Window, Graph_lib::Button, Graph_lib::Address) and then (b) adding using namespace Graph_lib; just below the #include's in Simple_window.cpp

(this latter prob. might not happen with FLTK 1.1, but FLTK 1.3 is the current stable release.)

Warnings:
There were a number of small defects which shouldn't have been there. Generally
- order of class member variable declaration cf. their order in the initializer list)
- use of int as the loop variable when testing against vector::size() -- when they should be size_t (or maybe a re-typedef of std::vector::size_type).

There was also a warning from gcc about hash_map begin deprecated. When I tried to switch to unordered_map it warned me that was still a prototype. So I went bask to hash+_map and added -Wno-deprecated to the compiler options.

[andywestken]

Note I did not add <string.h> as grumpy suggested in the cboard thread mentioned by bl4cbb3rry. But that's because I had FLTK 1.3 on my path already. grep-ing the code I can see Graph.h/.cpp are using FLTK (e.g. FL_RED, FL_GREEN, FL_BLUE, ... which are FLTK's color consts)

But it's benign - and that bit clearer - to add it, should you feel the need.

[andywestken]

To fix the errors and warnings, I did the following:

Graph.h

#1 warning: swapped the order of variable declaration in struct Color to

    Fl_Color c;
    char v;    // invisible and visible for now 

#2 warning: altered index type for the loop in ~Vector_ref() to size_t

#3 warning: altered size() to return a size_t

#4 error: fixed the no-copy code to

private:	// prevent copying
	Vector_ref(const Vector_ref&);
	Vector_ref& operator=(const Vector_ref&);

#5 warning: swapped the order of variable declaration in struct Rectangle to

    int w;    // width
    int h;    // height 

#6 error: removed the body of struct Circle, constructor, leaving definition in cpp file

#7 error: ditto for Circle's center() method

Graph.cpp

#1 warning: changed type of index variable for loop in Shape::draw_lines() to size_t.

#2 warning: ditto for Shape::move()

#3 warning: ditto for get_encoding()

Simple_Window.h

#1 error: commenting out the using namespace Graph_lib;

#2 error: namespace qualified all the types variables with Graph_lib types : Graph_lib::Window, Graph_lib::Button, Graph_lib::Address)

Simple_Window.cpp

#1 error: added using namespace Graph_lib; just below the #include's

Window.cpp

#1 warning: changed type of index variable for loop in Window::draw() to size_t.

#2 warning: changed type of index variable for loop in Window::put_on_top() to size_t. )

Makefile.txt

#1 misc: renamed it to just "makefile"

#2 warning: added -Wno-deprecated to the compiler command line

I also added FLTK=/local/include to the top of the makefile, so I did not have to modify my existing build environment, which in MinGW in this case (with FLTK installed in the default location using "make install")

[bl4ckb3rry]

Well, thank you Andy, I removed most of the errors.... But after I've done all that, I started getting this error:

Simple_window.obj : error LNK2001: unresolved external symbol "public: virtual void __thiscall
Graph_lib::Button::attach(class Graph_lib::Window &)" (?attach@Button@Graph_lib@@UAEXAAVWindow@2@@Z)

[andywestken]

This is when building libbookgui.a?

I don't see this error, and I can see Button::attach is defined correctly.

Are you using gcc? Or vc? Or?

EDIT: going by the linker error, it's vc!

Andy

GUI.h

    struct Button : Widget {
        Button(Point xy, int w, int h, const string& label, Callback cb)
            : Widget(xy,w,h,label,cb)
        {}

        void attach(Window&);
    };

GUI.cpp

void Button::attach(Window& win)
{
    pw = new Fl_Button(loc.x, loc.y, width, height, label.c_str());
    pw->callback(reinterpret_cast<Fl_Callback*>(do_it), &win); // pass the window
    own = &win;
}

[bl4ckb3rry]

*while looking at his feet he stutters:*
I haven't put GUI.cpp into my project, only GUI.h, so that's why I got linker error.

After that I compiled it successfully. Thank you so much!

[andywestken]

Have you downloaded the zip file with all the source for the chapters and FLTK, etc?

(I mean the "Complete collection of code fragments (revised)" link)

I can see the source for the GUI files, which we're been talking about, are a little bit different.