does making static inline inside namespace is redundant-CodePudding

is there any significance of making a variable and function inline and static inside a namespace. For example consider following 2 files:

consider first header file

// header1.h
#include <string>
#include <iostream>
namespace First
{
    static inline std::string s {"hi"};

    static inline void print(std::string str)
    {
        std::cout << str << std::end;
    }
}

and consider following second header file

// header2.h
#include <string>
#include <iostream>
namespace Second
{
    std::string s {"hi"};

    void print(std::string str)
    {
        std::cout << str << std::end;
    }
}

Does compiler see two codes differently or they introduce similar behavior ?

CodePudding user response：

Do not namespace variables and functions have internal linkage, like unnamed namespace ?

No, your assumption that namespace(named namespaces) variables and functions by default have internal linkage is incorrect.

Does compiler sees two codes differently or they introduce similar behavior ?

The one with thestatic keyword have internal linkage while the other(in header2.h) have external linkage.

That is, the variable s in header1.h and header2.h are distinct from each other. Similarly, the functions are also different from each other.

header1.h

namespace First
{
    static inline std::string s {"hi"};       //s has internal linkage

    static inline void print(std::string str) //print has internal linkage
    {
        std::cout << str << std::end;
    }
}

header2.h

namespace Second
{
    std::string s {"hi"};        //s has external linkage

    void print(std::string str)  //print has external linkage
    {
        std::cout << str << std::end;
    }
}