名称查找和访问检查

名称查找后发生重载分辨率。这意味着如果失去名称查找，则不会通过重载决策选择更好匹配的函数：

void f(int x);
struct S {
    void f(double x);
    void g() { f(42); } // calls S::f because global f is not visible here,
                        // even though it would be a better match
};

在访问检查之前发生过载分辨率。如果匹配比可访问函数更好，则可以通过重载决策选择不可访问的函数。

class C {
  public:
    static void f(double x);
  private:
    static void f(int x);
};
C::f(42); // Error! Calls private C::f(int) even though public C::f(double) is viable.

类似地，重载解析发生时不检查结果调用是否与 explicit 有关：

struct X {
    explicit X(int );
    X(char );
};

void foo(X );
foo({4}); // X(int) is better much, but expression is 
          // ill-formed because selected constructor is explicit