I need a set arranges the value in such a way that if the int values are different i need the lexographically greater string to come front else i want the smaller integer to come front
set<pair<int,string>,[&](auto &a,auto &b){
if(a.first==b.first)return a.second>b.second;
return a.first<b.first;
}>;
It seems you mean the following
#include <iostream>
#include <string>
#include <utility>
#include <set>
#include <tuple>
int main()
{
auto less = []( const auto &p1, const auto &p2 )
{
return std::tie( p1.first, p2.second ) <
std::tie( p2.first, p1.second );
};
std::set<std::pair<int, std::string>, decltype( less )>
s( { { 1, "A" }, { 1, "B" }, { 2, "A" } }, less );
for ( const auto &p : s )
{
std::cout << p.first << ' ' << p.second << '\n';
}
}
The program output is
1 B
1 A
2 A
You could use also the constructor without the initializer list
std::set<std::pair<int, std::string>, decltype( less )>
s( less );