fork download
copy 
  1. #include <vector>
  2. #include <iostream>
  3. #include <type_traits>
  4.  
  5. template<class ITERATORT,class ADAPTER>class IteratorAdapter : public ITERATORT {
  6.     ADAPTER adapter_;
  7.     public: IteratorAdapter(ITERATORT underlying,ADAPTER adapter) :
  8.         ITERATORT(underlying),
  9.         adapter_(adapter)
  10.     {   }
  11.     public: auto operator*(){
  12.         return adapter_(ITERATORT::operator*());
  13.     }
  14. };
  15. template<class COLLECTION,class ADAPTER>class CollectAdapter{
  16.     using CollectAdapterT=CollectAdapter<COLLECTION,ADAPTER>;
  17.     COLLECTION* collection_;    //<------ #1  problem?
  18.     ADAPTER adapter_;
  19.     public: CollectAdapter(COLLECTION& collection,ADAPTER adapter){
  20.         collection_=&collection;
  21.         adapter_=adapter;
  22.     }
  23.     public: auto begin(){
  24.         return IteratorAdapter<
  25.             decltype(std::declval<COLLECTION>().begin()),
  26.             decltype(adapter_)>
  27.             (collection_->begin(),adapter_);
  28.     }
  29.     public: auto end(){
  30.         return IteratorAdapter<
  31.             decltype(std::declval<COLLECTION>().end()),
  32.             decltype(adapter_)>
  33.             (collection_->end(),adapter_);
  34.     }
  35. };
  36. class CollectAdapterWidget{
  37.     public: template<class COLLECTION,class ADAPTER> static CollectAdapter<COLLECTION,ADAPTER> createAdapter(COLLECTION& collection,ADAPTER adapter){
  38.         return CollectAdapter<COLLECTION,ADAPTER>(collection,adapter);
  39.     }
  40. };
  41.  
  42.  
  43. int func1(int i){
  44.     return i+10;
  45. }
  46. int func2(int i){
  47.     return i+100;
  48. }
  49. template<class T> auto utilityAdapter(const T& t){
  50. 	auto adapter1=CollectAdapterWidget::createAdapter(t,func1);
  51. 	auto adapter12=CollectAdapterWidget::createAdapter(adapter1,func2);
  52. 	return adapter12;
  53. }
  54. int main(){
  55.     std::vector<int> test;
  56.     test.push_back(5);
  57.     std::cout<<"start"<<std::endl;
  58.     //for(auto b:CollectAdapterWidget::createAdapter(test,func1)){
  59.  
  60.     for(auto b:utilityAdapter(test)
  61.     ){
  62.  
  63.         std::cout<< b<<std::endl;
  64.     }
  65.     std::cout<<"end"<<std::endl;
  66. }
Runtime error #stdin #stdout 0s 15240KB
comments (?)
stdin
copy 
Standard input is empty
stdout
copy 
start
https://ideone.com/zMXXcu
language:
C++14 (gcc 8.3)
created:
7 years ago
visibility:
public

Share or Embed source code

Discover > Sphere Engine API

The brand new service which powers Ideone!

Discover > IDE Widget

Widget for compiling and running the source code in a web browser!