FP: duplInheritedMember and missingOverride when using namespace

[Dan Workman]

We've had this issue for many releases so can't provide a version that it started

Running
cppcheck --std=c++20 --enable=style,warning --template=gcc repro.cpp
on

namespace Legacy
{
struct Base
{
  int Count() const;
  virtual void Print() const;
  virtual ~Base() = default;
};

struct Position : Base
{
};
}

using namespace Legacy;

namespace Modern
{
struct Position
{
  int Count() const;
  void Print() const;
};
}

gives

repro.cpp:21:7: warning: The struct 'Position' defines member function with name 'Count' also defined in its parent struct 'Base'. [duplInheritedMember]
    int Count() const;
            ^
repro.cpp:5:7: note: Parent function 'Base::Count'
    int Count() const;
            ^
repro.cpp:21:7: note: Derived function 'Position::Count'
    int Count() const;
            ^
repro.cpp:22:8: warning: The function 'Print' overrides a function in a base class but is not marked with a 'override' specifier. [missingOverride]
    void Print() const;
             ^
repro.cpp:6:16: note: Virtual function in base class
    virtual void Print() const;
                             ^
repro.cpp:22:8: note: Function in derived class
    void Print() const;
             ^

We hit this regularly as we are slowly replacing a legacy implementation with a modern one and the two implementations differ only by namespace

[CHR]

Thanks for reporting, ticket is here: https://trac.cppcheck.net/ticket/15088