Overloading operator= for struct members of class std::vector<> - c++

Question

Say I have the following struct:
struct Parameter {
double value;
double error;
};
So that I'm usually working with vectors of that struct (ie. std::vector<Parameter>), and ocasionally I want to set a vector of values (but not errors) in that vector of parameters by using the operator= with a standard std::vector, for convenience.
std::vector<Parameter> vector_of_parameters;
std::vector<double> vector_of values;
....
vector_of_parameters = vector_of_values;
To do so, I'm trying to overload operator= for this struct as follows:
std::vector<Parameter> operator=(const std::vector<double>& v) {
this->clear();
for (const auto& i:v) {
Parameter p;
p.value = i;
this->push_back(p);
}
return *this;
}
But this will return an error saying that std::vector operator=(const std::vector& v) must be a non-static member. So if I understand it correctly, I have to define this as a member function of the operator as:
std::vector<Parameter>::operator=(const std::vector<double>& v) {
this->clear();
for (const auto& i:v) {
Parameter p;
p.value = i;
this->push_back(p);
}
return *this;
}
The error now says that a syntaxis with template<>, but I dont really see it, or understand it, and don't know what more can I do.

Answer 1

You cannot overload the assignment operator of std::vector. operator = must be a member function and you just can't add a member function to std::vector.
What you can do is make a convenience function like create_parameters that takes a std::vector<double> and returns a std::vector<Parameter>. That would look like
std::vector<Parameter> create_parameters(std::vector<double> const& params)
{
std::vector<Parameter> ret(params.size());
std::transform(params.begin(), params.end(), ret.begin(),
[](auto value) { return Parameter{value, 0}; });
return ret;
}
and then
vector_of_parameters = vector_of_values;
would become
vector_of_parameters = create_parameters(vector_of_values);

Answer 2

I think that an alternative simple way to create std::vector<Parameter> from std::vector<double> is defining a single argument constructor Parameter(double value) which accepts the Parameter::value:
#include <vector>
#include <optional>
struct Parameter
{
double value;
std::optional<double> error;
explicit Parameter(double v) : value(v)
{}
};
Then you can use range-constructor as follows:
DEMO
std::vector<Parameter> v_of_parameters(v_of_values.cbegin(), v_of_values.cend());