How to use an initializer_list to create a C++ <array> of structures?

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?

Shafik Yaghmour · Accepted Answer · 2018-11-10 13:36:08Z

2

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.

edited Nov 10, 2018 at 13:36

answered Nov 10, 2018 at 0:00

Shafik Yaghmour

160k44 gold badges466 silver badges778 bronze badges

Sign up to request clarification or add additional context in comments.

Collectives™ on Stack Overflow

How to use an initializer_list to create a C++ <array> of structures?

1 Answer 1

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

Comments

Your Answer

Sign up or log in

Post as a guest

Related