The min, max and minmax functions

This family of functions allows us to find the minimum and maximum in a set of data. Let's find out how.

We'll cover the following

Required Headers

The many variations of the min, max, and minmax functions apply to values and initializer lists. These functions need the header <algorithm>. Nearly the same holds for the functions std::move, std::forward and std::swap. You can apply them to arbitrary values. These three functions are defined in the header <utility>.

std::min, std::max and std::minmax

The functions std::min, std::max and std::minmax, defined in the header <algorithm>, act on values and initialiser lists and give you the requested value back as result. In the case of std::minmax, you get an std::pair. The first element of the pair is the minimum, the second is the maximum of the values. By default, the less operator (<) is used, but you can specify your comparison operator. This function needs two arguments and returns a boolean. Functions that either return true or false are called predicates.

// minMax.cpp
#include <iostream>
#include <algorithm>
//...
using std::cout;
//...
int main(){
  cout << "std::min(2011, 2014):\t\t\t ";
  cout << std::min(2011, 2014)<<"\n";                           // 2011
  
  cout << "std::min({3, 1, 2011, 2014, -5}):\t";
  cout << std::min({3, 1, 2011, 2014, -5})<<"\n";               // -5
  
  cout << "std::min(-10, -5, [](...) {...}):\t\t";
  cout << std::min(-10, -5, [](int a, int b)
                { return std::abs(a) < std::abs(b); })<<"\n\n"; // -5
  std::pair<int, int> pairInt= std::minmax(2011, 2014);
  auto pairSeq= std::minmax({3, 1, 2011, 2014, -5});
  auto pairAbs= std::minmax({3, 1, 2011, 2014, -5}, [](int a, int b)
                      { return std::abs(a) < std::abs(b); });
  cout << "pairInt.first, pairInt.second:\t\t";
  cout << pairInt.first << ", " << pairInt.second << "\n"; // 2011,2014
  
  cout << "pairSeq.first, pairSeq.second:\t\t";
  cout << pairSeq.first << ", " << pairSeq.second << "\n";  // -5,2014
  
  cout << "pairAbs.first, pairAbs.second:\t\t ";
  cout << pairAbs.first << ", " << pairAbs.second << "\n";  // 1,2014
  
  return 0;
}

The table provides an overview of the functions std::min, std::max and std::minmax

Function Description
min(a, b) Returns the minimal value of a and b.
min(a, b, comp) Returns the minimal value of a and b according to the predicate comp.
min(initializer list) Returns the minimal value of the initializer list.
min(initializer list, comp) Returns the minimal value of the initializer list according to the predicate comp.
max(a, b) Returns the maximal value of a and b.
max(a, b, comp) Returns the maximal value of a and b according to the predicate comp.
max(initializer list) Returns the maximal value of the initializer list.
max(initializer list, comp) Returns the maximal value of the initializer list according to the predicate comp.
minmax(a, b) Returns the minimal and maximal value of a and b.
minmax(a, b, comp) Returns the minimal and maximal value of a and b according to the predicate comp according to the predicate comp.
minmax(initializer list) Returns the minimal and maximal value of the initializer list.
minmax(initializer list, comp) Returns the minimal and maximal value of the initializer list according to the predicate comp.

The variations of `std::min`, `std::max` and `std::minmax`

Now, let’s talk about another useful function the std::move.