Question

I can’t manage to figure out why I get an error for the following code:

template <typename T>
class Test{
    void foo(vector<T>& v);
};

template <typename T>
void Test<T>::foo(vector<T>& v){
    //DO STUFF
}

int main(){
      Test<int> t;
      t.foo(vector<int>());
}

This is the error:

main.cpp: In function ‘int main()’:
main.cpp:21:21: error: no matching function for call to ‘Test<int>::foo(std::vector<int, std::allocator<int> >)’
main.cpp:21:21: note: candidate is:
main.cpp:14:6: note: void Test<T>::foo(std::vector<T>&) [with T = int]
main.cpp:14:6: note:   no known conversion for argument 1 from ‘std::vector<int, std::allocator<int> >’ to ‘std::vector<int, std::allocator<int> >&’

What am I doing wrong?

Answer 1

You can’t bind a temporary to a non-const reference.

Either change your signature to:

void foo(vector<T> const& v);

or don’t pass a temporary:

vector<int> temp;
t.foo(temp);