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  1. #include <iostream>
  2.  
  3. template<int n>
  4. struct bob
  5. {
  6.     bob() {
  7.         std::cout << "bob" << n << " reporting in\n";
  8.     };
  9. };
  10.  
  11. struct bar {
  12.     template<int n>
  13.     void Do() const {
  14.         bob<n> b;
  15.     };
  16. };
  17.  
  18. template<int n=0,int bit=9>
  19. struct foo
  20. { 
  21.     template<typename F>
  22.     void Do(unsigned int x,F&& f) {
  23.         if ((x>>bit)&1) {
  24.             foo<(n<<1)|1,bit-1>().Do(x,f);
  25.         }
  26.         else {
  27.             foo<(n<<1),bit-1>().Do(x,f);
  28.         };
  29.     };
  30. };
  31.  
  32. template<int n>
  33. struct foo<n,-1>
  34. {
  35.     template<typename F>
  36.     void Do(unsigned int x,F&& f) const {
  37.         f.template Do<n>();
  38.     };
  39. };
  40.  
  41. template<typename F>
  42. void mojo(int x, F&& f)
  43. {
  44.     foo<>()(x,f);
  45. }
  46.  
  47. int main()
  48. {
  49.     mojo(7,bar());
  50. }
  51.  
Compilation error #stdin compilation error #stdout 0s 0KB
comments (?)
stdin
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Standard input is empty
compilation info 
prog.cpp: In function 'void mojo(int, F&&) [with F = bar]':
prog.cpp:49:17:   instantiated from here
prog.cpp:44:5: error: no match for call to '(foo<>) (int&, bar&)'
stdout
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Standard output is empty
https://ideone.com/sVVvHS
language:
C++14 (gcc 8.3)
created:
11 years ago
visibility:
secret

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