main.cpp中的int main()一行报错，报错信息是[Error] a function-definition is not allowed here before '{' token
**main.cpp关键代码如下：**：
#include <stdio.h>
#include <iostream>
#include <string>
#include <sstream>
#include <fstream>
#include <list>
#include <vector>
#include "include.h"
using namespace std;
int main () {
//((FileCatalogLoader) catalogLoader).loadCatalog("catalog.txt");
cout << "Welcome to the vending machine" << endl;
//run();
//writeFile("catalog.txt",catalogFormatter.formatCatalog(catalog));
return 0;
}
```
**include.h代码如下：**
#include "Catalog.h"
#include "CatalogLoader.h"
#include "DataCatalogFormatter.h"
#include "DataSalesFormatter.h"
#include "Drink.h"
#include "FileCatalogLoader.h"
#include "Food.h"
#include "OperatorCatalogLoader.h"
#include "Order.h"
#include "OrderItem.h"
#include "Password.h"
#include "Product.h"
#include "Sales.h"
#include "Vault.h"
extern Catalog* catalog;
catalog = Catalog::getSingletonInstance();
extern Sales* sales;
sales = Sales::getSingletonInstance();
extern Password* pw;
pw = Password::getSingletonInstance();
extern Vault* vault;
vault = Vault::getSingletonInstance();
extern CatalogLoader* catalogLoader;
catalogLoader = FileCatalogLoader::getSingletonInstance();
extern DataSalesFormatter* salesFormatter;
salesFormatter = DataSalesFormatter::getSingletonInstance();
extern DataCatalogFormatter* catalogFormatter;
catalogFormatter = DataCatalogFormatter::getSingletonInstance();
报错情况：
main.cpp中的int main()一行报错，报错信息是[Error] a function-definition is not allowed here before '{' token
对于这个错误，网上查的都是函数中定义函数、缺括号或分号导致的，可是我的代码不存在以上的问题，那是为什么出错呢？
另外，我把头文件#include "include.h"去掉，这块就不报错了，这是为什么呢？
希望有人能帮我解答一下这个问题，非常感谢！
