std::modulus<void>

Since C++14

Header: <functional>

std::modulus is a specialization of std::modulus with parameter and return type deduced.

# Declarations

template<>
class modulus<void>;

(since C++14)

# Parameters

# Return value

std::forward(lhs) % std::forward(rhs).

# Example

#include <functional>
#include <iostream>
 
struct M
{
    M(int x) { std::cout << "M(" << x << ");\n"; }
    M() {}
};
 
auto operator%(M, M) { std::cout << "operator%(M, M);\n"; return M{}; }
auto operator%(M, int) { std::cout << "operator%(M, int);\n"; return M{}; }
auto operator%(int, M) { std::cout << "operator%(int, M);\n"; return M{}; }
 
int main()
{
    M m;
 
    // 42 is converted into a temporary object M{42}
    std::modulus<M>{}(m, 42);    // calls operator%(M, M)
 
    // no temporary object
    std::modulus<void>{}(m, 42); // calls operator%(M, int)
    std::modulus<void>{}(42, m); // calls operator%(int, M)
}