c++ - 标准的哪一部分确定就地成员与初始化列表的优先级？

Question

我只是做了一个样例，从我个人的观点来看应该是不能编译的，或者至少要给出警告，但是Visual Studio 2017并没有给出任何警告。示例如下:

#include <stdexcept>

struct Foo {
    Foo(int i) { throw std::runtime_error("Oh no:("); }
    Foo(float f) {}
};

struct Bar {
    Bar() {}
};

struct Baz {
    Baz() : foo(5.0f) {}

    Bar bar;
    Foo foo = Foo(3);
    Bar bar2;
};

int main()
{
    Baz baz;
}

在我看来(但我不是语言律师)，foo 的两个初始化(in-place vs initializer list)是模棱两可的。那么这种情况下的规则是什么？

Answer 1

明确首选构造函数中提供的值。

[class.base.init]/10: If a given non-static data member has both a default member initializer and a mem-initializer, the initialization specified by the mem-initializer is performed, and the non-static data member's default member initializer is ignored.