Functional template (function template) in C + +

C + + templates (template) are the basis of generic programming (generic programming);

Object-oriented programming is known as type (type) when running (run time); Generic programming is compiler (compilation) knows the type;

Functions template (function template) contains a list of template parameters (template parameter list);

Each parameter type must precede the keyword TypeName or class, use TypeName as much as possible, and express the meaning more clearly;

Non-type template parameters (Nontype Template Parameters) can only be integer types, pointers, references;

The integral type must be a constant expression (constant expression), and the pointer and reference must point to a static type;

Template functions need to guarantee the type of function independent (type independence) and portability (portability); Use STL library function as far as possible;

Code:

* * * cppprimer.cpp * * Created on:2013.11.21 * author:caroline//*eclipse CDT, gcc 4.8.1*/ #include <iostream> #include <vector> #include <functional>//less<> #include <cstrin g>//strcmp template <typename t> int compare (const t &AMP;V1, const T &v2) {if (Std::le Ss<t> () (v1, v2)) return-1;  
    Using a library function instead of "<" avoids pointer address comparisons if (std::less<t> () (v2, v1)) return 1;  
return 0;  
    } template<unsigned N, unsigned m> int compare (const char (&AMP;P1) [N], const char (&AMP;P2) [M]) { Std::cout << "n =" << N << "m =" << m << Std::endl; Add a null terminator (null terminator) return std::strcmp (P1, p2);  
    Compare only the first character} int main (void) {std::cout << compare (1, 0) << Std::endl;  
    Std::vector<int> V1{1, 2, 3}, V2{4, 5, 6};  Std::cout << Compare (v1, v2) << Std::endl;
    Std::cout << Compare ("Girl", "lad") << Std::endl;  
    int a[] = {1, 2, 3, 4}, b[] = {1, 3, 4, 5};  
      
    Std::cout << Compare (A, b) << Std::endl;  
      
return 0; }

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