Implicit conversion from std::vector<std::shared_ptr<T>> to std::vector<std::shared_ptr<const T>>

I have a function requiring const std::vector<std::shared_ptr<const T>>& as signature. It seems that compiler doesn’t allow me to pass in a std::vector<std::shared_ptr<T>>. Wondering why it cannot implicitly convert from std::vector<std::shared_ptr<T>> to std::vector<std::shared_ptr<const T>>.

I tried passing an object of std::vector<std::shared_ptr<T>> to a function requiring const std::vector<std::shared_ptr<const T>>& as signature. It fails to compile.

>Solution :

Since there is no implicit conversion between std::vectors with different template arguments. Just write helper function:

–
Marek R

class Foo {};

std::vector<std::shared_ptr<const Foo>> convert(const std::vector<std::shared_ptr<Foo>>& v)
{
    return {v.begin(), v.end()};
}