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  1. #include <functional>
  2.  
  3. namespace _dtl {
  4.  
  5.     template <typename FUNCTION> struct
  6.     _curry;
  7.  
  8.     // specialization for functions with a single argument
  9.     template <typename R,typename T> struct
  10.     _curry<std::function<R(T)>> {
  11.         using
  12.         type = std::function<R(T)>;
  13.  
  14.         const type
  15.         result;
  16.  
  17.         _curry(type fun) : result(fun) {}
  18.  
  19.     };
  20.  
  21.     // recursive specialization for functions with more arguments
  22.     template <typename R,typename T,typename...Ts> struct
  23.     _curry<std::function<R(T,Ts...)>> {
  24.         using
  25.         remaining_type = typename _curry<std::function<R(Ts...)> >::type;
  26.  
  27.         using
  28.         type = std::function<remaining_type(T)>;
  29.  
  30.         const type
  31.         result;
  32.  
  33.         _curry(std::function<R(T,Ts...)> fun)
  34.         : result (
  35.             [=](const T& t) {
  36.                 return _curry<std::function<R(Ts...)>>(
  37.                     [=](const Ts&...ts){ 
  38.                         return fun(t, ts...); 
  39.                     }
  40.                 ).result;
  41.             }
  42.         ) {}
  43.     };
  44. }
  45.  
  46. template <typename R,typename...Ts> auto
  47. curry(const std::function<R(Ts...)> fun)
  48. -> typename _dtl::_curry<std::function<R(Ts...)>>::type
  49. {
  50.     return _dtl::_curry<std::function<R(Ts...)>>(fun).result;
  51. }
  52.  
  53. template <typename R,typename...Ts> auto
  54. curry(R(* const fun)(Ts...))
  55. -> typename _dtl::_curry<std::function<R(Ts...)>>::type
  56. {
  57.     return _dtl::_curry<std::function<R(Ts...)>>(fun).result;
  58. }
  59.  
  60. #include <iostream>
  61.  
  62. void 
  63. f(std::string a,std::string b,std::string c)
  64. {
  65.     std::cout << a << b << c;
  66. }
  67.  
  68. int 
  69. main() {
  70.     curry(f)("Hello ")("functional ")("world!");
  71.     return 0;
  72. }
Success #stdin #stdout 0s 3280KB
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Standard input is empty
stdout
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Hello functional world!
https://ideone.com/CQ8ELv
removed illegitimate double underscores
language:
C++14 (gcc 8.3)
created:
9 years ago
visibility:
public

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