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Don’t blindly prefer emplace_back to push_back

(quuxplusone.github.io)
178 points todsacerdoti | 1 comments | 04 Mar 21 08:02 UTC | HN request time: 0.431s | source
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MauranKilom ◴[04 Mar 21 12:01 UTC] No.26341332[source]▶
Random emplace_back hate: I really dislike how you can't use it for objects that you'd normally use aggregate initialization for.

See https://godbolt.org/z/6qW7q3

    struct SimpleData
    {
        int a;
        double b;
    };

    SimpleData someData = {1, 2.0}; // ok

    std::vector<SimpleData> data;

    // Why can I not do this?
    data.emplace_back(1, 2.0);
replies(3): >>26341692 #>>26344690 #>>26347384 #
1. gpderetta ◴[04 Mar 21 19:58 UTC] No.26347384[source]▶
That's because of the epic fail that are initializer lists that prevent aggregate initialization (which is otherwise awesome) to be used safely in generic contextes.