相关疑难解决方法(0)

我无法理解依赖于参数(Koenig)查找的规则.

请考虑以下代码:

#include <iostream>

using namespace std;

namespace adl
{
    struct Test { };
    void foo1(Test const &) { cout << "ADL used (foo1)" << endl; }
    void foo2(Test const &) { cout << "ADL used (foo2)" << endl; }
    void foo3(Test const &) { cout << "ADL used (foo3)" << endl; }
}

struct foo1
{
    foo1() { }

    template<class T>
    foo1(T const &) { cout << "ADL not used (foo1)" << endl; }

    template<class T>
    void operator()(T const …