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关于std::initalizer_list和auto
The C++ Programming Language(Strostrup,4th edition,P165)有这种用法:
auto x3{1,2,3};
Visual Studio 2015 RC2下：
auto i{2};
//auto ii{2, 2};
//error C3518: 'ii': in a direct-list-initialization
//context the type for 'auto' can only be
//deduced from a single initializer expression
auto iii={2,2,2};
typeid(i).name()得出结果为int
typeid(iii).name()得出结果为class std::initalizer_listint
Cppreference:
In direct-list-initialization (but not in copy-list-initalization), when deducing the meaning of the auto from a braced-init-list, the braced-init-list must contain only one element, and the type of auto will be the type of that element:
auto x1 = {3}; // x1 is std::initializer_listint
auto x2{1, 2}; // error: not a single element
auto x3{3}; // x3 is int (before C++17 it was std::initializer_listint)
C++14标准文档暂时没找到解释。
所以应该是书的问题吧，但是为什么就是不可以呢？auto不就是为了推断类型吗？希望各位有研究的吧友们指明
（尤其是标准文档中的说明
）。
楼主 2016-06-16 11:34 回复
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