Example use of Lambda expressions and for ranges with C++11

example.cpp

#include <algorithm>
#include <iostream>
#include <string>
#include <vector>

using namespace std;

void FindValue(vector<string>& values, std::function<bool (const string&)> f)
{
    auto i = find_if(values.begin(), values.end(), f);
    
    if (values.end() == i)
    {
        cout << "Unable to find value" << endl;
    }
    else
    {
        cout << "Found: " << *i << endl;
    }
}

vector<string> FindIfLength(const vector<string>& values, function<bool (const string&, const unsigned int)> f, const int length)
{
    vector<string> results;
    for (auto i : values)
    {
        if (f(i, length))
        {
            results.push_back(i);
        }
    }
    
    return results;
}

int main (int argc, char** argv)
{
    vector<string> v1 = { "Hello", "World",  "Information"};
    
    FindValue(v1, [] (const string& s) { return s == "Hello"; } );
    FindValue(v1, [] (const string& s) { return s == "World"; } );
    FindValue(v1, [] (const string& s) { return s == "Bob"; } );
    
    for (auto s : FindIfLength(v1, [] (const string& s, const unsigned int i) -> bool { return s.length() >= i; }, 7))
    {
        cout << "Found: " << s << endl;
    }
    
    return 0;
}

Compiled on Ubuntu 11.10 (GCC 4.6.1) using the following switches:

g++ --std=c++0x -Wall -Werror -O2 -o example example.cpp