Push_back causing an error when using vectors in C++

Question

I am having issues getting this piece of code to compile. I am compiling with Eclipse on OS X 10.6. The problem seems to occur only when using vectors. I cannot seem to use the push_back function at all. Every time I try, I get the error "expected constructor, destructor, or type conversion before '.' token". Here are a few snippets of my code:

#include <GLUT/glut.h>
#include <vector>
#include <stdlib.h>
#include <iostream>
#include <math.h>
using namespace std;
enum Colour {BLACK =0, RED=1, BLUE=2, GREEN=3, PURPLE=4, ORANGE=5, CYAN=6, BLANK=7};

class Point {
private:
    GLfloat xval, yval;
public:
    Point(float x =0.0, float y = 0.0){
        xval=x;
        yval=y;
    }

    GLfloat x() {return xval;}
    GLfloat y() {return yval;}
};


class LinePoint {
private:
    Point p;
    Colour cNum;
public:
    LinePoint(Point pnt = Point(0,0), Colour c = BLACK){
        cNum = c;
        p = pnt;
    }
    Point getPoint(){return p;}
    Colour getColour(){return cNum;}
};
float turtleScale = 20;
Point turtlePos = Point(300./turtleScale,200./turtleScale);
LinePoint* lp = new LinePoint(turtlePos,BLACK);

vector<LinePoint*> lines;

lines.push_back(lp);

I'm not sure if this would have anything to do with how Eclipse is setup but it also seems that if I use the code located here, in place of my vector calls, it still compiles with the same error.

Kornel Kisielewicz · Accepted Answer · 2010-01-30 01:41:28Z

10

Here:

float turtleScale = 20;
Point turtlePos = Point(300./turtleScale,200./turtleScale);
LinePoint* lp = new LinePoint(turtlePos,BLACK);

vector<LinePoint*> lines;

... you use initializations, but this:

lines.push_back(lp);

... is a statement! It must live in a function :)

int main()
{
    lines.push_back(lp);
}

... will work.

edited Jan 30, 2010 at 1:41

answered Jan 30, 2010 at 0:52

Kornel Kisielewicz

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3 Comments

fastrack20 Over a year ago

And I am officially a noob :) Thanks for the help, I am new to C++ and didn't know this fact.

UncleBens Over a year ago

Technically the rest are initializations. Assignments wouldn't be allowed either.

R Samuel Klatchko Over a year ago

@UncleBen & @Kornel - what makes those legal outside a function is that they are definitions.

R Samuel Klatchko · Accepted Answer · 2010-01-30 00:52:02Z

4

You can't have a statement outside of a function. So this line:

 lines.push_back(lp);

needs to be placed in a function.

It's okay to have definitions outside of a function, which is why these lines are okay:

float turtleScale = 20;
Point turtlePos = Point(300./turtleScale,200./turtleScale);
LinePoint* lp = new LinePoint(turtlePos,BLACK);

answered Jan 30, 2010 at 0:52

R Samuel Klatchko

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Comments

Max Shawabkeh · Accepted Answer · 2010-01-30 00:52:32Z

4

Unless it's a typo, you have code in the open, outside of any function. This is not allowed in C++. You have to put it in a function or method instead. If you want it to run right away, put it in an int main() { ...}.

answered Jan 30, 2010 at 0:52

Max Shawabkeh

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