Subject: Re: [boost] task_array<n> and variadic templates
From: vicente.botet (vicente.botet_at_[hidden])
Date: 2008-11-19 11:39:30
----- Original Message -----
From: "Yechezkel Mett" <ymett.on.boost_at_[hidden]>
To: <boost_at_[hidden]>
Sent: Wednesday, November 19, 2008 4:51 PM
Subject: Re: [boost] task_array<n> and variadic templates
>
> On Wed, Nov 19, 2008 at 5:32 PM, Yechezkel Mett
> <ymett.on.boost_at_[hidden]> wrote:
>> On Wed, Nov 19, 2008 at 5:08 PM, Vicente Botet <vicente.botet_at_[hidden]> wrote:
>
> On a current compiler:
>
> template <std::size N>
> struct task_array {
> task arr_[N];
> template <typename... F>
> task_array(F... f) {
> static_assert(sizeof...(T) == N, "Constructor must provide N parameters")
> boost::array<task, N> arr = { task(f)... };
> std::copy(arr.begin(), arr.end(), arr_);
> }
> };
>
> if you don't mind the multiple copies -- perhaps better to move rather
> than copy.
>
> Recursion isn't too bad either:
>
> namespace detail
> {
> template<typename T, typename Head, typename... Tail>
> void fill_array(T* arr, Head h, Tail... t) {
> *arr = T(h);
> fill_array(arr + 1, t...);
> }
>
> template<typename T>
> void fill_array(T* arr) {}
> }
>
> template <std::size N>
> struct task_array {
> task arr_[N];
> template <typename... F>
> task_array(F... f) {
> static_assert(sizeof...(T) == N, "Constructor must provide N parameters")
> detail::fill_array(arr_, f...);
> }
> };
I will try both, changing the c array by boos::array
Thanks,
Vicente