Clang-Tidy: Redundant 'operator<<' declaration
1
I was trying to write a friend operator<< to my class and I got this warning of redundant. And can't figure how to fix it.
Thank you in advance.
#include <iostream>
using namespace std;
template<class T>
class test
{
public:
explicit test(T a) noexcept : m_{ a } {}
template <class Y>
//line below shows that warning.
friend std::ostream& operator<<(std::ostream& out, const test<Y>& lhs);
private:
T m_;
};
template<class Y>
std::ostream& operator<<(std::ostream& out, const test<Y>& lhs)
{
out << lhs.m_ << endl;
return out;
}
int main()
{
test<int> p {25};
test<double> q {17.5};
std::cout << "By Friend " << p;
std::cout << "By Friend " << q;
return 0;
}
Edit 1
//Removed template Y from the operator<< int he class declaration
template<class T>
class test
{
public:
explicit test(T a) noexcept : m_{ a } {}
friend std::ostream& operator<< (std::ostream&, const test<T>&);
private:
T m_;
};
template<class T>
std::ostream& operator<<(std::ostream& out, const test<T>& lhs)
{
out << lhs.m_ << endl;
return out;
}
now I got a Warning
warning: friend declaration 'std::ostream& operator<<(std::ostream&, const test&)' declares a non-template function [-Wnon-template-friend]
PS : in Visual Studio I got Error Links
EDIT 1.2 //edit done for EDIT 1
I changed the Edit 1 as follow :
....
friend std::ostream& operator<< <> (std::ostream&, const test<T>&);
....
So warnings and error links are resolved.
c++ templates clang-tidy
asked Nov 13 '18 at 11:34
Blood-HaZaRdBlood-HaZaRd
92621032
|
show 11 more comments
1
I was trying to write a friend operator<< to my class and I got this warning of redundant. And can't figure how to fix it.
Thank you in advance.
#include <iostream>
using namespace std;
template<class T>
class test
{
public:
explicit test(T a) noexcept : m_{ a } {}
template <class Y>
//line below shows that warning.
friend std::ostream& operator<<(std::ostream& out, const test<Y>& lhs);
private:
T m_;
};
template<class Y>
std::ostream& operator<<(std::ostream& out, const test<Y>& lhs)
{
out << lhs.m_ << endl;
return out;
}
int main()
{
test<int> p {25};
test<double> q {17.5};
std::cout << "By Friend " << p;
std::cout << "By Friend " << q;
return 0;
}
Edit 1
//Removed template Y from the operator<< int he class declaration
template<class T>
class test
{
public:
explicit test(T a) noexcept : m_{ a } {}
friend std::ostream& operator<< (std::ostream&, const test<T>&);
private:
T m_;
};
template<class T>
std::ostream& operator<<(std::ostream& out, const test<T>& lhs)
{
out << lhs.m_ << endl;
return out;
}
now I got a Warning
warning: friend declaration 'std::ostream& operator<<(std::ostream&, const test&)' declares a non-template function [-Wnon-template-friend]
PS : in Visual Studio I got Error Links
EDIT 1.2 //edit done for EDIT 1
I changed the Edit 1 as follow :
....
friend std::ostream& operator<< <> (std::ostream&, const test<T>&);
....
So warnings and error links are resolved.
c++ templates clang-tidy
asked Nov 13 '18 at 11:34
Blood-HaZaRdBlood-HaZaRd
92621032
1
So it's clang-tidy, and not clang? What rule triggers this?
– Matthieu Brucher
Nov 13 '18 at 11:38
1
@Useless : the actual warning says : Clang-Tidy: Redundant 'operator<<' declaration in the operator<< funct declared in the class
– Blood-HaZaRd
Nov 13 '18 at 11:39
1
@paddy : it is the case where all friend template instanciations are friend with all class template instansiation. Edit : So I removed the templated Y and I got a warningwarning: friend declaration 'std::ostream& operator<<(std::ostream&, const test<T>&)' declares a non-template function [-Wnon-template-friend]
– Blood-HaZaRd
Nov 13 '18 at 11:50
1
Have you tried removingtemplate <class Y>from the class declaration? (Use T instead of Y at the implementation)
– JVApen
Nov 13 '18 at 11:55
1
@JVApen : Please look at Edit 1 (hope did what you meant)
– Blood-HaZaRd
Nov 13 '18 at 11:59
|
show 11 more comments
1
1
1
I was trying to write a friend operator<< to my class and I got this warning of redundant. And can't figure how to fix it.
Thank you in advance.
#include <iostream>
using namespace std;
template<class T>
class test
{
public:
explicit test(T a) noexcept : m_{ a } {}
template <class Y>
//line below shows that warning.
friend std::ostream& operator<<(std::ostream& out, const test<Y>& lhs);
private:
T m_;
};
template<class Y>
std::ostream& operator<<(std::ostream& out, const test<Y>& lhs)
{
out << lhs.m_ << endl;
return out;
}
int main()
{
test<int> p {25};
test<double> q {17.5};
std::cout << "By Friend " << p;
std::cout << "By Friend " << q;
return 0;
}
Edit 1
//Removed template Y from the operator<< int he class declaration
template<class T>
class test
{
public:
explicit test(T a) noexcept : m_{ a } {}
friend std::ostream& operator<< (std::ostream&, const test<T>&);
private:
T m_;
};
template<class T>
std::ostream& operator<<(std::ostream& out, const test<T>& lhs)
{
out << lhs.m_ << endl;
return out;
}
now I got a Warning
warning: friend declaration 'std::ostream& operator<<(std::ostream&, const test&)' declares a non-template function [-Wnon-template-friend]
PS : in Visual Studio I got Error Links
EDIT 1.2 //edit done for EDIT 1
I changed the Edit 1 as follow :
....
friend std::ostream& operator<< <> (std::ostream&, const test<T>&);
....
So warnings and error links are resolved.
c++ templates clang-tidy
asked Nov 13 '18 at 11:34
Blood-HaZaRdBlood-HaZaRd
92621032
I was trying to write a friend operator<< to my class and I got this warning of redundant. And can't figure how to fix it.
Thank you in advance.
#include <iostream>
using namespace std;
template<class T>
class test
{
public:
explicit test(T a) noexcept : m_{ a } {}
template <class Y>
//line below shows that warning.
friend std::ostream& operator<<(std::ostream& out, const test<Y>& lhs);
private:
T m_;
};
template<class Y>
std::ostream& operator<<(std::ostream& out, const test<Y>& lhs)
{
out << lhs.m_ << endl;
return out;
}
int main()
{
test<int> p {25};
test<double> q {17.5};
std::cout << "By Friend " << p;
std::cout << "By Friend " << q;
return 0;
}
Edit 1
//Removed template Y from the operator<< int he class declaration
template<class T>
class test
{
public:
explicit test(T a) noexcept : m_{ a } {}
friend std::ostream& operator<< (std::ostream&, const test<T>&);
private:
T m_;
};
template<class T>
std::ostream& operator<<(std::ostream& out, const test<T>& lhs)
{
out << lhs.m_ << endl;
return out;
}
now I got a Warning
warning: friend declaration 'std::ostream& operator<<(std::ostream&, const test&)' declares a non-template function [-Wnon-template-friend]
PS : in Visual Studio I got Error Links
EDIT 1.2 //edit done for EDIT 1
I changed the Edit 1 as follow :
....
friend std::ostream& operator<< <> (std::ostream&, const test<T>&);
....
So warnings and error links are resolved.
c++ templates clang-tidy
c++ templates clang-tidy
asked Nov 13 '18 at 11:34
Blood-HaZaRdBlood-HaZaRd
92621032
asked Nov 13 '18 at 11:34
Blood-HaZaRdBlood-HaZaRd
92621032
edited Nov 13 '18 at 12:31
Blood-HaZaRd
asked Nov 13 '18 at 11:34
Blood-HaZaRdBlood-HaZaRd
92621032
asked Nov 13 '18 at 11:34
Blood-HaZaRdBlood-HaZaRd
92621032
asked Nov 13 '18 at 11:34
Blood-HaZaRdBlood-HaZaRd
92621032
92621032
1
So it's clang-tidy, and not clang? What rule triggers this?
– Matthieu Brucher
Nov 13 '18 at 11:38
1
@Useless : the actual warning says : Clang-Tidy: Redundant 'operator<<' declaration in the operator<< funct declared in the class
– Blood-HaZaRd
Nov 13 '18 at 11:39
1
@paddy : it is the case where all friend template instanciations are friend with all class template instansiation. Edit : So I removed the templated Y and I got a warningwarning: friend declaration 'std::ostream& operator<<(std::ostream&, const test<T>&)' declares a non-template function [-Wnon-template-friend]
– Blood-HaZaRd
Nov 13 '18 at 11:50
1
Have you tried removingtemplate <class Y>from the class declaration? (Use T instead of Y at the implementation)
– JVApen
Nov 13 '18 at 11:55
1
@JVApen : Please look at Edit 1 (hope did what you meant)
– Blood-HaZaRd
Nov 13 '18 at 11:59
|
show 11 more comments
1
So it's clang-tidy, and not clang? What rule triggers this?
– Matthieu Brucher
Nov 13 '18 at 11:38
1
@Useless : the actual warning says : Clang-Tidy: Redundant 'operator<<' declaration in the operator<< funct declared in the class
– Blood-HaZaRd
Nov 13 '18 at 11:39
1
@paddy : it is the case where all friend template instanciations are friend with all class template instansiation. Edit : So I removed the templated Y and I got a warningwarning: friend declaration 'std::ostream& operator<<(std::ostream&, const test<T>&)' declares a non-template function [-Wnon-template-friend]
– Blood-HaZaRd
Nov 13 '18 at 11:50
1
Have you tried removingtemplate <class Y>from the class declaration? (Use T instead of Y at the implementation)
– JVApen
Nov 13 '18 at 11:55
1
@JVApen : Please look at Edit 1 (hope did what you meant)
– Blood-HaZaRd
Nov 13 '18 at 11:59
1
1
So it's clang-tidy, and not clang? What rule triggers this?
– Matthieu Brucher
Nov 13 '18 at 11:38
So it's clang-tidy, and not clang? What rule triggers this?
– Matthieu Brucher
Nov 13 '18 at 11:38
1
1
@Useless : the actual warning says : Clang-Tidy: Redundant 'operator<<' declaration in the operator<< funct declared in the class
– Blood-HaZaRd
Nov 13 '18 at 11:39
@Useless : the actual warning says : Clang-Tidy: Redundant 'operator<<' declaration in the operator<< funct declared in the class
– Blood-HaZaRd
Nov 13 '18 at 11:39
1
1
@paddy : it is the case where all friend template instanciations are friend with all class template instansiation. Edit : So I removed the templated Y and I got a warning
warning: friend declaration 'std::ostream& operator<<(std::ostream&, const test<T>&)' declares a non-template function [-Wnon-template-friend]– Blood-HaZaRd
Nov 13 '18 at 11:50
@paddy : it is the case where all friend template instanciations are friend with all class template instansiation. Edit : So I removed the templated Y and I got a warning
warning: friend declaration 'std::ostream& operator<<(std::ostream&, const test<T>&)' declares a non-template function [-Wnon-template-friend]– Blood-HaZaRd
Nov 13 '18 at 11:50
1
1
Have you tried removing
template <class Y> from the class declaration? (Use T instead of Y at the implementation)– JVApen
Nov 13 '18 at 11:55
Have you tried removing
template <class Y> from the class declaration? (Use T instead of Y at the implementation)– JVApen
Nov 13 '18 at 11:55
1
1
@JVApen : Please look at Edit 1 (hope did what you meant)
– Blood-HaZaRd
Nov 13 '18 at 11:59
@JVApen : Please look at Edit 1 (hope did what you meant)
– Blood-HaZaRd
Nov 13 '18 at 11:59
|
show 11 more comments
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1
So it's clang-tidy, and not clang? What rule triggers this?
– Matthieu Brucher
Nov 13 '18 at 11:38
1
@Useless : the actual warning says : Clang-Tidy: Redundant 'operator<<' declaration in the operator<< funct declared in the class
– Blood-HaZaRd
Nov 13 '18 at 11:39
1
@paddy : it is the case where all friend template instanciations are friend with all class template instansiation. Edit : So I removed the templated Y and I got a warning
warning: friend declaration 'std::ostream& operator<<(std::ostream&, const test<T>&)' declares a non-template function [-Wnon-template-friend]– Blood-HaZaRd
Nov 13 '18 at 11:50
1
Have you tried removing
template <class Y>from the class declaration? (Use T instead of Y at the implementation)– JVApen
Nov 13 '18 at 11:55
1
@JVApen : Please look at Edit 1 (hope did what you meant)
– Blood-HaZaRd
Nov 13 '18 at 11:59