Поиск в файле информации о подарках

#include <iostream>
#include <string>
#include <map>
#include <fstream>
#include <sstream>
 
using namespace std;
string normalize_spaces(const string& text){
    string res;
    size_t beg=0, end = text.size();
    for(; beg<text.size() && isspace(text[beg]); ++beg)  ;
    if (beg < end){
        --end;
        for(; end>beg && isspace(text[end]); --end)  ;
        res = text.substr(beg, (end+1) - beg);
    }
    return res;
}
int main()
{
    map<string, double> shop_goods;
    { // load from file
        istringstream iss;
        ifstream file("presents.shop");
        if (file.is_open()){
            string line, name; double price;
            while(getline(file, line)){
                iss.str(line);
                if(getline(iss, name, '=') && iss>>price)
                    shop_goods[normalize_spaces(name)] = price;
                iss.clear();
                iss.str("");
            }
        }
        else 
            // do something if file not opening
        ;
    }
    if (shop_goods.empty()){
        cout << "No presents, come later. Goodbye :)";
        return 0;
    }
    // goods list
    cout << "Goods in marlet : " << endl;
    for (const auto & present : shop_goods)
        cout << present.first << " : " <<present.second << endl;
    cout << endl;
    
    { // present choice
        string name; double price;
        cout << "Enter presnt name you wish : " ; getline(cin, name);
        cout << "Enter your money : " ; cin >> price;
        auto present = shop_goods.find(name);
        if (present != shop_goods.end()){
            if (price >= present->second)  // YEH! I wonna this !
                cout << "Your may buy this present. " << endl
                     << present->first << " for the " << present->second << "$" << endl;
            else
                cout << "Your have no money for that." << endl;
        }
        else
            cout << "No good with this name" << endl;
    }
}