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//#include <iostream>
 
template <class T1>
class A {};
 
class B : public A<int> {};
 
template <template <class T1> class T, class T1 >
void func1(T<T1> _arg) {}
 
template <class T1, class T2>
class C {};
 
template <class T1>
class D : public C<T1,int> {};
 
template <template <class T1, class T2> class T, class T1, class T2>
void func2(T<T1,T2> _arg) {}
 
 
int main() {
    A<int> a;
    B b;
    func1(a);//works
    func1(b);//doesn't work
 
#if 0
    C<float,int> c;
    D<float> d;
    func2(c);//works
    func2(d);//doesn't work,compilation error message: "Candidate template ignored: substitution failure : template template argument has different template parameters than its corresponding template template parameter"
#endif
    return 0;
}
 

prog.cpp: In function ‘int main()’:
prog.cpp:25:12: error: no matching function for call to ‘func1(B&)’
     func1(b);//doesn't work
            ^
prog.cpp:25:12: note: candidate is:
prog.cpp:9:6: note: template<template<class T1> class T, class T1> void func1(T<T1>)
 void func1(T<T1> _arg) {}
      ^
prog.cpp:9:6: note:   template argument deduction/substitution failed:
prog.cpp:25:12: note:   can't deduce a template for ‘T<T1>’ from non-template type ‘B’
     func1(b);//doesn't work
            ^

Standard output is empty