개요
예제
#include <algorithm>
#include <cstring>
#include <iostream>
#include <string>
#include <string_view>
#include <type_traits>
using namespace std;
class A {};
class B {
public:
B() {}
B(const B &b) {}
};
class C {
public:
C() {}
C(const C &c) noexcept {}
};
class D {
public:
D() {}
D(const D &d) = delete;
};
void swap(A &a, B &b) {}
template <typename T> constexpr string_view type_name() {
const string s = __PRETTY_FUNCTION__;
const int prefixSize = s.find("[with T = ") + strlen("[with T = ");
return string_view(s.data() + prefixSize, s.find(';') - prefixSize);
}
int main() {
auto func1 = [](auto t) {
cout << "is_swappable<" << type_name<decltype(t)>() << ">::value - "
<< is_swappable<decltype(t)>::value << endl;
cout << "is_nothrow_swappable<" << type_name<decltype(t)>()
<< ">::value - " << is_nothrow_swappable<decltype(t)>::value
<< endl;
};
auto func2 = [](auto t1, auto t2) {
cout << "is_swappable_with<" << type_name<decltype(t1)>() << ", "
<< type_name<decltype(t2)>() << ">::value - "
<< is_swappable_with<decltype(t1), decltype(t2)>::value << endl;
cout << "is_nothrow_swappable_with<" << type_name<decltype(t1)>()
<< ", " << type_name<decltype(t2)>() << ">::value - "
<< is_nothrow_swappable_with<decltype(t1), decltype(t2)>::value
<< endl;
};
func1(int());
cout << "------" << endl;
func1(A());
cout << "------" << endl;
func1(B());
cout << "------" << endl;
func1(C());
cout << "------" << endl;
func1(D());
cout << "------" << endl;
func2(int(), int());
cout << "------" << endl;
func2(int(), A());
cout << "------" << endl;
func2(A(), B());
cout << "------" << endl;
func2(C(), D());
return 0;
}
is_swappable<int>::value - 1
is_nothrow_swappable<int>::value - 1
------
is_swappable<A>::value - 1
is_nothrow_swappable<A>::value - 1
------
is_swappable<B>::value - 1
is_nothrow_swappable<B>::value - 0
------
is_swappable<C>::value - 1
is_nothrow_swappable<C>::value - 1
------
is_swappable<D>::value - 0
is_nothrow_swappable<D>::value - 0
------
is_swappable_with<int, int>::value - 0
is_nothrow_swappable_with<int, int>::value - 0
------
is_swappable_with<int, A>::value - 0
is_nothrow_swappable_with<int, A>::value - 0
------
is_swappable_with<A, B>::value - 0
is_nothrow_swappable_with<A, B>::value - 0
------
is_swappable_with<C, D>::value - 0
is_nothrow_swappable_with<C, D>::value - 0
