c ++初始化列表和可变参数模板
我想创建一个数组：
template < typename T, typename ... A > struct a {
T x [1 + sizeof... (A)];
a () = default;
a (T && t, A && ... y) : x { t, y... } {}
};
int main () {
a < int, int > p { 1, 1 }; // ok
a < a < int, int >, a < int, int > > q { { 1, 1 }, { 3, 3 } }; // error: bad array initializer
}
没有找到相关结果
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1 个回复
玖料萄
{}为构造函数提供参数。因此你的代码应该没问题：int main () { // this is fine, calls constructor with {1, 1}, {3, 3} a<a<int, int>, a<int, int>> q({ 1, 1 }, { 3, 3 }); // which in turn needs to construct a T from {1, 1}, // which is fine because that's the same as: a<int, int>{1, 1}; // same as: a<int, int>(1, 1); // and that's trivially okay (and tested in your code) // we do likewise with A..., which is the same as above // except with {3, 3}; and the values don't affect it }