directory

1、tuple

2, function

3, test

1、tuple

Tuple extends Pair to see the function of two elements as a unit, and realize the function that can treat any number of elements as a unit.

2, function

tuple <T1, t2 ... tn> t; Create Tuple with N given elements 
 Tuple <T1, t2 ... tn> t (v1, v2 ... vn); build tuple and initialize 
 Tuple <T1, T2> T (PAIR); Create a TPLE, with two elements 
 t = t2; assign the value t2 to T 
 t = Pair; assign pair to TPLE with two elements 
 T1 == T2; compare all elements 
 T1! = T2 
 T1 <T2 
 T1> T2 
 T1 <= t2 
 t1> = t2 
 t1.swap (t2); 
 swap (t1, t2); 
 make_tuple (v1, v2 ...); build Tuple to pass the type 
 tie (ref (1) ...; build a tuple composed of reference

3, test

#include <iOSTREAM> 
 #include <Tuple> 
 #include <string> 
 using namespace std; 

 template <th IDX, int Max, Typename ... ARGS> 
 struct Print_tuple { 
 Static Void Print (OSTREAM & OS, Const Tuple <args ...> & T) 
 {{ 
 OS << get <idx> (t) << (IDX + 1 == max? "": ":", "); 
 // recursion 
 Print_tuple <IDX + 1, MAX, ARGS ...> :: Print (OS, T); 
 } 
 }; 

 // End of recursion 
 template <th Max, Typename ... ARGS> 
 struct print_tuple <max, max, args ...> 
 {{ 
 Static Void Print (OSTREAM & OS, Const Tuple <args ...> & T) 
 {{ 

 } 
 }; 

 // Reight -load operation operating symbols << 
 template <typename ... args> 
 OSTREAM & Operator << (OSTREAM & OS, Const Tuple <args ...> & T) 
 {{ 
 os << "[";; 
 Print_tuple <0, sizeof ... (args), args ...> :: Print (OS, T); 
 Return os << "];; 
 } 

 int Main () 
 {{ 
 // Create 
 tuple <int, char, string> t; 
 t = Make_tuple (1, 'a', "abc"); 
 COUT << Get <0> (t) << ENDS << GET <1> (t) << ENDS <2> (t) .c_str () << Endl; 

 // Take your value 
 int a = 0; 
 char ch1 = ''; 
 String Str; 
 tie (a, ch1, str) = t; 
 copy << ENDS << ch1 << ENDS << Str.c_str () << Endl; 

 // This operation is not allowed, and implicit conversion is not allowed 
 // vector <Tuple <int, char, string >> v {{1, 'a', "abc"}, {2, 'b', "def"}}; 
 
 core << t << Endl; 

 // Get the element type 
 tuple_element <0, decltype (t)> :: Type ages; 
 // Get the number of elements 
 COUT << Tuple_size <Deckype (T)> :: Value << Endl; 
 System ("pause"); 
 }