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    <p>Based on @Xeo's <a href="https://stackoverflow.com/a/13315884/819272">excellent idea</a>, here is an approach that lets you fill an array of</p> <ul> <li><code>constexpr std::array&lt;T, N&gt; a = { fun(0), fun(1), ..., fun(N-1) };</code></li> <li>where <code>T</code> is any literal type (not just <code>int</code> or other valid non-type template parameter types), but also <code>double</code>, or <code>std::complex</code> (from C++14 onward)</li> <li>where <code>fun()</code> is any <code>constexpr</code> function</li> <li>which is supported by <code>std::make_integer_sequence</code> from C++14 onward, but easily implemented today with both g++ and Clang (see Live Example at the end of the answer)</li> <li>I use @JonathanWakely 's <a href="https://gitorious.org/redistd/integer_seq/raw/fdce85d18df4ea99240524c626d5452a0f7c3faf:integer_seq.h" rel="noreferrer">implementation at GitHub</a> (Boost License)</li> </ul> <p>Here is the code</p> <pre><code>template&lt;class Function, std::size_t... Indices&gt; constexpr auto make_array_helper(Function f, std::index_sequence&lt;Indices...&gt;) -&gt; std::array&lt;typename std::result_of&lt;Function(std::size_t)&gt;::type, sizeof...(Indices)&gt; { return {{ f(Indices)... }}; } template&lt;int N, class Function&gt; constexpr auto make_array(Function f) -&gt; std::array&lt;typename std::result_of&lt;Function(std::size_t)&gt;::type, N&gt; { return make_array_helper(f, std::make_index_sequence&lt;N&gt;{}); } constexpr double fun(double x) { return x * x; } int main() { constexpr auto N = 10; constexpr auto a = make_array&lt;N&gt;(fun); std::copy(std::begin(a), std::end(a), std::ostream_iterator&lt;double&gt;(std::cout, ", ")); } </code></pre> <p><a href="http://coliru.stacked-crooked.com/a/663dee82db2aef0a" rel="noreferrer"><strong>Live Example</strong></a></p>
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    1. CO`where auto is any literal type` Isn't it a `std::array` of literal types, in `auto a = make_array<N>(fun);`, equivalent to `auto a = std::array<decltype(fun(0)), N>{fun(0), fun(1), ..};`? Also, the example `constexpr auto a = {1,2};` deduces `a` to be a `std::initializer_list`, which isn't yet required to be a literal type (-> no `constexpr`). (I know it's rather pedantic, but I was confused at first glance.)
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