Thread: Searching string within vector struct C++ 11

Hello,

new to C++ lambda, got two question in regards of searching for strings within a vector struct.

Minimalistic example:

Code:

struct singleFile {
    std::string filename;
};

std::vector<singleFile>myStorage;

myStorage.push_back(singleFile());
myStorage.push_back(singleFile());
myStorage.push_back(singleFile());
myStorage[0].filename = "file0";
myStorage[1].filename = "file1";
myStorage[2].filename = "file2";


auto it = std::find_if(std::begin(myStorage), std::end(myStorage), [] (myStorage const& f)
    { 
    return (f.filename == "file1"); 
    });
bool found = (it != std::end(myStorage));

1) why does found always return 0 eventhough the filename exists?
2) I don't know how to pass an actual search string instead of the hardcoded approach as above with filename =="bla" :/ could you give me some hints by any chance?

thx in advance=)

thanks alot!:D

1) ah was just a typo sry:) I think the issue is me making wrong use of the bool found thus having 0 returned all time:/
basic example:

Code:

#include <stdio.h>
#include <string>
#include <iostream>    
#include <algorithm>   
#include <vector>    


struct singleFile {
    std::string filename;
};
 
std::vector<singleFile>myStorage;
 

std::string subject = "file2";
auto it = std::find_if(begin(myStorage), end(myStorage), [&subject](const singleFile& f)
{
    return f.filename == subject;
});

bool found = (it != std::end(myStorage));

int main()
{
    myStorage.push_back(singleFile());
    myStorage.push_back(singleFile());
    myStorage.push_back(singleFile());
    myStorage[0].filename = "file0";
    myStorage[1].filename = "file1";
    myStorage[2].filename = "file2";
    if (found) std::cout << "Found!" << std::endl;
    return 0;
}

meh I'm stupid... bool found = (it != std::end(myStorage)); obviously won't return anything but 0 if the declaration is before the push+naming of the files... >< thx again

hm one final question:
sounds quite simple, but how can I actually get the position or value of the iterator of my vector struct?

for instance

Code:

    if (found) 
         std::cout << *it << std::endl;

would work if it was vector<int>myVec; instead of vector<singleFile>myVec;

basically all I would need is the position of the found object (i.e. 1 for vector[1]) =/