CODEWITHSUNDEEP
c++c++11initializer-list
Marinos K
Marinos K

Reputation: 1819

use std::initialiser_list to explicitly initialise a variable

this code 

std::initializer_list<const char*> list {"something", "somthingElse" /*..*/};
const char* array[] = list;

fails to compile with the following error on error: 

array initializer must be an initializer list

Can't really understand what I'm doing wrong here since I'm using an initializer_list after all.

(The reason I use an initializer_list is so I can use list.size() later in my code in several parts; it'd be error_prone having to adjust a series of magic constants each time I add/remove something from the list)

Upvotes: 2

Views: 167

Answers (1)

Toby Speight
Toby Speight

Reputation: 30834

To initialize an array, you need a brace-enclosed initializer list which is not the same as a std::initializer_list.

To get what you're trying to achieve, you could use a std::array, but you'll need a helper function to deduce its size parameter:

#include <array>

template<typename T, typename... Ts>
constexpr std::array<T, sizeof...(Ts)> make_array(Ts... i)
{
    return {i...};
}

int main() {
    auto a = make_array<const char*>( "a", "b", "c", "d" );
    return a.size(); // I get an exit value of 4 here
}

Upvotes: 1

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