Defined in header <algorithm> | ||
---|---|---|
(1) | ||
template< class T > const T& max( const T& a, const T& b ); | (until C++14) | |
template< class T > constexpr const T& max( const T& a, const T& b ); | (since C++14) | |
(2) | ||
template< class T, class Compare > const T& max( const T& a, const T& b, Compare comp ); | (until C++14) | |
template< class T, class Compare > constexpr const T& max( const T& a, const T& b, Compare comp ); | (since C++14) | |
(3) | ||
template< class T > T max( std::initializer_list<T> ilist ); | (since C++11) (until C++14) | |
template< class T > constexpr T max( std::initializer_list<T> ilist ); | (since C++14) | |
(4) | ||
template< class T, class Compare > T max( std::initializer_list<T> ilist, Compare comp ); | (since C++11) (until C++14) | |
template< class T, class Compare > constexpr T max( std::initializer_list<T> ilist, Compare comp ); | (since C++14) |
Returns the greater of the given values.
a
and b
. ilist
.Overloads (1,3) use operator<
to compare the values, overloads (2,4) use the given comparison function comp
.
a, b | - | the values to compare |
ilist | - | initializer list with the values to compare |
comp | - | comparison function object (i.e. an object that satisfies the requirements of Compare) which returns true if a is less than b . The signature of the comparison function should be equivalent to the following:
While the signature does not need to have |
Type requirements | ||
-T must meet the requirements of LessThanComparable in order to use overloads (1,3). |
||
-T must meet the requirements of CopyConstructible in order to use overloads (3,4). |
a
and b
. If they are equivalent, returns a
.ilist
. If several values are equivalent to the greatest, returns the leftmost one.ilist.size() - 1
comparisonsmax (1) |
---|
max (2) |
max (3) |
max (4) |
Capturing the result of std::max
by reference produces a dangling reference if one of the parameters is a temporary and that parameter is returned:
#include <algorithm> #include <iomanip> #include <iostream> #include <string_view> int main() { auto longest = [](const std::string_view s1, const std::string_view s2) { return s1.size() < s2.size(); }; std::cout << "Larger of 69 and 96 is " << std::max(69, 96) << "\n" "Larger of 'q', and 'p' is '" << std::max('q', 'p') << "'\n" "Largest of 010, 10, 0X10, and 0B10 is " << std::max({010, 10, 0X10, 0B10}) << '\n' << R"(Longest of "long", "short", and "int" is )" << std::quoted(std::max({"long", "short", "int"}, longest)) << '\n'; }
Output:
The following behavior-changing defect reports were applied retroactively to previously published C++ standards.
DR | Applied to | Behavior as published | Correct behavior |
---|---|---|---|
LWG 281 | C++98 | T was required to be CopyConstructible for overloads (1,2) | not required |
returns the smaller of the given values (function template) |
|
(C++11) | returns the smaller and larger of two elements (function template) |
returns the largest element in a range (function template) |
|
(C++17) | clamps a value between a pair of boundary values (function template) |
(C++20) | returns the greater of the given values (niebloid) |
© cppreference.com
Licensed under the Creative Commons Attribution-ShareAlike Unported License v3.0.
https://en.cppreference.com/w/cpp/algorithm/max