std::modulus<void>

 

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Operator wrappers plus minus negate multiplies divides modulus bit_and bit_or bit_not (C++14) bit_xor equal_to not_equal_to greater less greater_equal less_equal logical_and logical_or logical_not	Transparent operator wrappers plus<> (C++14) minus<> (C++14) negate<> (C++14) multiplies<> (C++14) divides<> (C++14) modulus<> (C++14) bit_and<> (C++14) bit_or<> (C++14) bit_not<> (C++14) bit_xor<> (C++14) equal_to<> (C++14) not_equal_to<> (C++14) greater<> (C++14) less<> (C++14) greater_equal<> (C++14) less_equal<> (C++14) logical_and<> (C++14) logical_or<> (C++14) logical_not<> (C++14)
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Defined in header <functional>
template<> class modulus<void>;		(since C++14)

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

Member types

Member type	Definition
is_transparent	/* unspecified */

Member functions

operator()

returns the modulus of two arguments (public member function)

std::modulus<>::operator()

template< class T, class U> constexpr auto operator()( T&& lhs, U&& rhs ) const   -> decltype(std::forward<T>(lhs) % std::forward<U>(rhs));

Returns the remainder of the division of lhs by rhs (or whatever operator% is overloaded to do)

Parameters

lhs, rhs

-

values to divide

Return value

The result of lhs % rhs.

Notes

The member type is_transparent indicates to the caller that this function object is a transparent function object: it accepts arguments of arbitrary types and uses perfect forwarding, which avoids unnecessary copying and conversion when the function object is used in heterogeneous context, or with rvalue arguments. In particular, template functions such as std::set::find and std::set::lower_bound make use of this member type on their Compare types.

Example

Run this code

#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 m1, m2;
 
    m1 % m2;
    m1 % 42;
    42 % m1;
 
    std::modulus<M>{}(m1, 42); // 42 is converted into a temporary M{42}
    std::modulus<> {}(m1, 42); // no temp. object, calls operator% (M, int)
    std::modulus<> {}(42, m1); // no temp. object, calls operator% (int, M)
}

Output:

operator% (M, M);
operator% (M, int);
operator% (int, M);
M(42);
operator% (M, M);
operator% (M, int);
operator% (int, M);