Question

I have:

struct MyStruct
{
   char* name;
   int* somethingElse;
};

And I need to find in a std::vector<MyStruct*> an element (by using std::find_if) whose name is "XYZ" … but … the Predicate of std::find_if (if I have managed to understand it correctly) is a plain function, and it takes in a MyStruct pointer and I have no idea where I can specify the extra "XYZ" value to be used in the comparison.

So, how can I use std::find_if or this purpose? (Obviously, looking for a nice solution, not a global variable, or just walk through the list, ….)

Thanks, f

Answer 1

You can use a functor for this (hope I didn’t get anything wrong, as I typed it in the browser):

class finder
{
     const char* name;
public:
    finder(const char* _name): name(_name) {}

    bool operator()(MyStruct* elem) {return strcmp(elem->name, name) == 0;}
};

finder f("sample");
std::find_if(myvector.begin(), myvector.end(), f);