c++ - variadic multidimensional array -

could call multidimensional array like

func(0,0,0); //=> if know it's dimension on run time.  func(0,0,0,0,0,0,0,0,0,0,0); //=> if know it's dimension on run time.  

through of variadic templates

instead of:

data[0][0][0]; data[0][0][0][0][0][0][0][0][0][0][0]; 

this should work instead of doing data[1][2][3] have use indexed(data,1,2,3)

it works plain arrays std::arrays. can extend std::vector duplicating specializations. (i think should work thing overloads operator[] not sure.)

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#include <iostream> #include <array>  template<typename t, size_t dim> struct gettypeatdim { typedef t type; };  template<typename t, size_t n> struct gettypeatdim<t[n],1> { typedef t type; };  template<typename t, size_t dim, size_t n> struct gettypeatdim<t[n],dim> : gettypeatdim< t, dim-1> {};  template<typename t, size_t n> struct gettypeatdim<std::array<t,n>,1> { typedef t type; };  template<typename t, size_t dim, size_t n> struct gettypeatdim<std::array<t,n>,dim> : gettypeatdim< t, dim-1> {};  template<typename t, size_t dim> using typeatdim = typename gettypeatdim<t, dim>::type;  template<typename t>  typeatdim<t,1>& indexed(t& arr, const int& first) {     return arr[first]; }  template<typename t, typename... args>  typeatdim<t,sizeof...(args) + 1>&  indexed(t& arr, const int& first, const args& ...rest) {     return indexed(arr[first],rest...); } 

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int main() {     std::array<int,2> a1 = {1,2};     std::array<int,2> a2 = {3,4};     std::array<std::array<int,2>,2> = {a1,a2};     std::array<std::array<std::array<int,2>,2>,2> c = {a,a};     int b[2][2] = {{5,6},{7,8}};       std::cout << indexed(a,1,1) << std::endl;     indexed(a,1,1) = 5;     std::cout << indexed(a,1,1) << std::endl;     std::cout << indexed(b,1,1) << std::endl;     std::cout << indexed(c,1,1,1) << std::endl;     indexed(c,1,1) = a1;     std::cout << indexed(c,1,1,1) << std::endl; } 

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4 5 8 4 2 

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here test run.

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i not using auto trailing return types because the variadic version of indexed not match when deducing type of return. until gets resolved gcc have use this.