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  1. #include <iostream>
  2. #include <type_traits>
  3.  
  4. struct A
  5. {
  6.     template < typename T >
  7.     typename std::enable_if< std::is_pointer<T>::value, void >::type
  8.     foo( const T& v )
  9.     { std::cout << "A::foo( const T& p ) - T is a pointer, *p == " << *v << '\n' ; }
  10.  
  11.     template < typename T >
  12.     typename std::enable_if< !std::is_pointer<T>::value, void >::type
  13.     foo( const T& v )
  14.     { std::cout << "A::foo( const T& v ) - T is not a pointer, v == " << v << '\n' ; }
  15.  
  16.     template < typename T, std::size_t N >
  17.     void foo( const T(&array)[N] )
  18.     {
  19.         std::cout << "A::foo( const T(&array)[" << N << "] ): " ;
  20.         for( const auto& v : array ) std::cout << v << ' ' ;
  21.         std::cout << '\n' ;
  22.     }
  23.  
  24.     template < typename T >
  25.     void foo( const T array[], std::size_t n )
  26.     {
  27.         std::cout << "A::foo( const T array[], n ) - n == " << n << ": " ;
  28.         for( std::size_t i = 0 ; i < n ; ++i ) std::cout << array[i] << ' ' ;
  29.         std::cout << '\n' ;
  30.     }
  31. };
  32.  
  33. int main()
  34. {
  35.     double d[5] = { 1.1, 2.3, 3.3, 4.4, 5.5 } ;
  36.     A a ;
  37.  
  38.     a.foo( d[3] ) ; // A::foo( const T& v ) - T is not a pointer, v == 4.4
  39.     a.foo(d) ; // A::foo( const T(&array)[5] ): 1.1 2.3 3.3 4.4 5.5
  40.     a.foo( d, 5 ) ; // A::foo( const T array[], n ) - n == 5: 1.1 2.3 3.3 4.4 5.5
  41.     a.foo( +d ) ; // A::foo( const T& p ) - T is a pointer, *p == 1.1
  42. }
  43.  
Success #stdin #stdout 0s 2852KB
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stdin
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Standard input is empty
stdout
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A::foo( const T& v ) - T is not a pointer, v == 4.4
A::foo( const T(&array)[5] ): 1.1 2.3 3.3 4.4 5.5 
A::foo( const T array[], n ) - n == 5: 1.1 2.3 3.3 4.4 5.5 
A::foo( const T& p ) - T is a pointer, *p == 1.1
https://ideone.com/Q0wxqV
language:
C++14 (gcc 8.3)
created:
10 years ago
visibility:
public

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