错误：&#39;类 std::vector<Shape*> &#39; 没有名为 &#39;sort&#39; 的成员

Question

I have a code where I am drawing different Shape , now there can be preference on which one to draw first among say Square, rectangle and triangle . I have override the "<" ( less than operator for base class Shape. My preference of drawing is in increasing order as mentioned in typeOrderTable. Therefore triangle will be drawn before Square But upon compilation I get the error error: 'class std::vector' has no member named 'sort'.

#include <iostream>
#include <vector>
#include <typeinfo>
#include <string.h>
using namespace std;


class Shape 
{ 
    public: 
    virtual void Draw() const = 0; 
    virtual bool Precedes(const Shape&) const ;
    bool operator<(const Shape& s) 
    {
        return Precedes(s);
    }
    private:    
    static char* typeOrderTable[];
};

char* Shape::typeOrderTable[] = {"Rectangle","Square","Triangle",0 };

bool Shape::Precedes(const Shape& s) const 
{
    const char* thisType = typeid(*this).name();    
    const char* argType = typeid(s).name();    
    bool done = false;    int thisOrd = -1;    
    int argOrd = -1;    
    for (int i=0; !done; i++)    
    {        
        const char* tableEntry = typeOrderTable[i];
        if (tableEntry != 0)        
        {            
            if (strcmp(tableEntry, thisType) == 0)                
            thisOrd = i;            
            if (strcmp(tableEntry, argType) == 0)                
            argOrd = i;
            if ((argOrd > 0) && (thisOrd > 0))                
            done = true;        

        }        
        else // table entry == 0            
        done = true;    
    }    
    return thisOrd < argOrd; 
}

class Square : public Shape 
{ 
    public: 
    virtual void Draw() const 
    { 
        std::cout << "Inside Draw of Square \n" ; 

    } 
};

class Rectangle : public Shape 
{ 
    public: 
    virtual void Draw() const 
    { 
        std::cout << "Inside Draw of Rectangle \n" ; 

    } 
};

class Triangle : public Shape 
{ 
    public: 
    virtual void Draw() const 
    { 
        std::cout << "Inside Draw of Triangle \n" ; 

    } 
};

void DrawAllShapes(std::vector<Shape*>& list) 
{        
    std::vector<Shape*> orderedList = list;
    orderedList.sort();    
    std::vector<Shape*>::iterator it =orderedList.begin();
    for (;it!=orderedList.end(); ++it)
    (*it)->Draw(); 
}

int main() 
{
std::vector<Shape*> vec;
vec.push_back(new Triangle);
vec.push_back(new Square);
vec.push_back(new Rectangle);
vec.push_back(new Square);
DrawAllShapes(vec);
return 0;
}

Answer 1

There is no std::vector<...>::sort . Instead, you will need to use std::sort :

std::sort(orderedList.begin(), orderedList.end());

However , this will try to compare the pointers in your std::vector<Shape*> (hint: refactor this if at all possible). Instead, you will need to pass a custom comparator that dereferences the pointers:

std::sort(
    orderedList.begin(),
    orderedList.end(),
    [](Shape *a, Shape *b) { return *a < *b; }
);