I added an underscore to my source code file name and now I got this error "error: definition of explicitly-defaulted ‘book_store::book_store()’ "

This source file book_store.h contains the class book_store but i recently changed the source file book_store.cpp from by adding the "_" between book and store so now i am getting the error described in the title

class book_store
{
    public:

        book_store() = default;
        void read_book_data(string);
        void process_orders(string);
        void print();
        int isbnSort(int []);

    private:
        int book[30];
        int validBooks = 0;

};

>Solution :

You probably changed something else.
The error tells you that you have defined your own constructor.

= default tells the compiler to use the default implementation. This also means that you cannot provide your own.