Can't access string in struct

Question

const struct config{
    private:
        std::string file;
        config() : file(getConfig()) {}
    public:
        std::string failsafe = file.substr(file.find("failsafe") + 12);
        failsafe.resize(failsafe.find("\""));
        size_t ran, price, expiry;
    } *ini;

Line 7 - Error: this declaration has no storage class or type specifier. I'm puzzled. Why can't I access failsafe?

You can't call functions like substr or resize inside a structure declaration. Use your constructor to do this. — Chnossos
– Chnossos, Commented Apr 13, 2014 at 2:17
You can't run code inside a struct like that. Everything except for declaring your fields has to be inside a function. — ApproachingDarknessFish
– ApproachingDarknessFish, Commented Apr 13, 2014 at 2:17

Othermusketeer · Accepted Answer · 2014-04-13 03:21:30Z

There are several problems with your code. I put your code, plus added some dummy code (ie: getConfig) into MSVC2010 to test and fix it.

In nearly all cases, Constructors ( config() ) have to be public. After all, how else will it be accessed to initialize the object. I moved the constructor to the Public area.
The code (find(), substr()) must be inside a function. Either main(), the constructor of the object, or some function/method. I moved your code into the constructor.
I did not add anything to handle errors (such as not finding the substrings you are looking for), but you may consider adding some code to handle those situations.

const struct config{
private:
    std::string file;
public:
    config() : file(getConfig()) {
        failsafe = file.substr(file.find("failsafe") + 12);
        failsafe.resize(failsafe.find("\""));
    }
    std::string failsafe;
    size_t ran, price, expiry;
} *ini;

Varaquilex · Accepted Answer · 2014-04-13 02:22:48Z

1

The reason Constructors are there is for initializing members, which you try to attempt when you are declaring them.

const struct config{
    private:
        std::string file;
        config() : file(getConfig()) {
            failsafe = file.substr(file.find("failsafe") + 12);
            failsafe.resize(failsafe.find("\""));
        }
    public:
        std::string failsafe; 
        size_t ran, price, expiry;
    } *ini;

answered Apr 13, 2014 at 2:22

Varaquilex

3,4737 gold badges42 silver badges61 bronze badges

1 Comment

M.M Over a year ago

The file.substr() line may not do what you intend if failsafe is not found in the string, it'd be better to store the result of find and check it was found before doing the substr.

Collectives™ on Stack Overflow

Can't access string in struct

2 Answers 2

Comments

1 Comment

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

Comments

1 Comment

Your Answer

Sign up or log in

Post as a guest

Related