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std::gcd

From cppreference.com
< cpp‎ | numeric
Defined in header <numeric>
template< class M, class N >
constexpr std::common_type_t<M, N> gcd( M m, N n );
(since C++17)

Computes the greatest common divisor of the integers m and n.

Contents

[edit] Parameters

m, n - integer values

[edit] Return value

If both m and n are zero, returns zero. Otherwise, returns the greatest common divisor of |m| and |n|.

[edit] Remarks

If either M or N is not an integer type, or if either is (possibly cv-qualified) bool, the program is ill-formed.

If either |m| or |n| is not representable as a value of type std::common_type_t<M, N>, the behavior is undefined.

[edit] Exceptions

Throws no exceptions.

[edit] Notes

Feature testing macro: __cpp_lib_gcd_lcm

[edit] Example

#include <numeric>
int main() {
    constexpr int p {2 * 2 * 3};
    constexpr int q {2 * 3 * 3};
    static_assert(2 * 3 == std::gcd(p, q));
}

[edit] See also

(C++17)
constexpr function template returning the least common multiple of two integers
(function template) [edit]