sorting a vector of objects c++ sorting a vector of objects c++ c++ sort vector of objects by property c++ sort vector of objects by property

#include 

#include 

using namespace std;
vector< MyStruct > values;
sort( values.begin( ), values.end( ), [ ]( const MyStruct& lhs, const MyStruct& rhs )

{

   return lhs.key < rhs.key;
});struct MyStruct
{
    int key;
    std::string stringValue;

    MyStruct(int k, const std::string& s) : key(k), stringValue(s) {}
};

struct less_than_key
{
    inline bool operator() (const MyStruct& struct1, const MyStruct& struct2)
    {
        return (struct1.key < struct2.key);
    }
};

std::vector < MyStruct > vec;
vec.push_back(MyStruct(4, “test”));

vec.push_back(MyStruct(3, “a”));

vec.push_back(MyStruct(2, “is”));

vec.push_back(MyStruct(1, “this”));
std::sort(vec.begin(), vec.end(), less_than_key());vector< cat > catSorter::SortCatsByAge(){

   vector< cat > cats_copy = cats;

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

   return cats_copy;

}class cat {

public:

    int age;

    bool operator< (const cat &other) const {
        return age < other.age;
    }
};