NAME¶

std::ranges::min_max_result - std::ranges::min_max_result

Synopsis¶

Defined in header <algorithm>
template< class T > (since C++20)
struct min_max_result;

ranges::min_max_result is a class template that provides a way to store two objects
or references of the same type as a single unit.

This class template has no base classes or declared members other than those shown
below. Thus it is suitable for use with structured bindings.

All special member functions of this class template are implicitly declared, which
makes specializations be aggregate classes, and propagate triviality,
potentially-throwing-ness, and constexpr-ness of corresponding operations on data
members.

Template parameters¶

T - the type of the objects or references that the ranges::min_max_result stores.

Data members

Member name Definition
may be a reference to, a copy of, or an iterator of type T to a minimum
min element in a range.
(public member object)
may be a reference to, a copy of, or an iterator of type T to a maximum
max element in a range
(public member object)

All these members are declared with [[no_unique_address]] attribute.

Member functions¶

std::ranges::min_max_result::operator min_max_result<T2>

template<class T2>

requires std::convertible_to<const T&, T2> (1)

constexpr operator min_max_result<T2>() const &;
template<class T2>

requires std::convertible_to<T, T2> (2)

constexpr operator min_max_result<T2>() &&;

Converts *this to the result by constructing every data member of the result from
the corresponding member of *this.

1) Equivalent to return {min, max};.
2) Equivalent to return {std::move(min), std::move(max)};.

Standard library¶

The following standard library functions use ranges::min_max_result as the return
type:

Algorithm functions
ranges::minmax returns the smaller and larger of two elements
(C++20) (niebloid)
ranges::minmax_element returns the smallest and the largest elements in a range
(C++20) (niebloid)

Synopsis¶

namespace std::ranges
{
template<class T>
struct min_max_result
{
[[no_unique_address]] T min;
[[no_unique_address]] T max;

template<class T2>
requires std::convertible_to<const T&, T2>
constexpr operator min_max_result<T2>() const &
{
return {min, max};
}

template<class T2>
requires std::convertible_to<T, T2>
constexpr operator min_max_result<T2>() &&
{
return {std::move(min), std::move(max)};
}
};
}

Notes¶

Each standard library algorithm that uses this family of return types declares a new
alias type, e.g. using merge_result = in_in_out_result<I1, I2, O>;.

The names for such aliases are formed by adding the suffix "_result" to the
algorithm's name. So, the return type of std::ranges::merge can be named as
std::ranges::merge_result.

Unlike std::pair and std::tuple, this class template has data members of meaningful
names.

Example¶

// Run this code

#include <algorithm>
#include <ranges>

int main()
{
constexpr static auto v = {3, 1, 4, 1, 5, 9, 2};
{
constexpr auto result = std::ranges::minmax(v);
static_assert(1 == result.min && 9 == result.max);
}
{
constexpr auto result = std::ranges::minmax_element(v);
static_assert(1 == *result.min && 9 == *result.max);
}
}

See also¶

pair implements binary tuple, i.e. a pair of values
(class template)
tuple implements fixed size container, which holds elements of possibly different
(C++11) types
(class template)