Here is an extract of C++ FAQ (section inherited constructors),

People sometimes are confused about the fact that ordinary scope rules
apply to class members. In particular, a member of a base class is not
in the same scope as a member of a derived class:

struct B {
    void f(double);
};
struct D : B {
    void f(int);
};
B b;   b.f(4.5);    // fine
D d;   d.f(4.5);    // surprise: calls f(int) with argument 4

As explained just after in the extract of the FAQ, you need to add using B::f in D to overload f correctly.

In fact, yes I’m confused : since method in struct are public by default, it is public in derived struct also (D share his methods with B). So, why does it not work the same as a normal overloaded function ?