如何使用initializer_list创建C ++ <array> 结构？

Question

The following code works as expected to initialize a vector of structs:

#include <array>
struct node
{
    std::string name;
    std::string value;
};

const std::vector<node> reqFields ({
    { "query", tmpEmail },
    { "firstname", firstName },
    { "lastname", lastName }
});

I want to optimize my code a bit to use a C++ 11 array instead, given that my data is static. However, the following won't compile:

const std::array<node, 3>({
    { "query", tmpEmail },
    { "firstname", firstName },
    { "lastname", lastName }
});

What is the right syntax to initialize the array? or maybe this is something that Visual Studio 15 has trouble with?

Answer 1

std::vector has a constructor that takes initializer_list :

vector( std::initializer_list<T> init,
    const Allocator& alloc = Allocator() ); 

but std::array is an aggregate and follows the rules of aggregate initialization .

So you need to switch from () to {}

const std::array<node, 3> reqFields {
    {{ "query", "tmp" },
    { "firstname", "firstName" },
    { "lastname", "lastName" }}
};

see it live on godbolt .