[C++ Error] Unit1.cpp(10): E2303 Type name expected

//---------------------------------------------------------------------------
 
#include <windows.h>
#include <iostream.h>
 
#include <vcl.h>
 
using namespace std;
 
void foo(int& num, mutex& mtx)
{
    while (1)
    {
        mtx.lock();
        num += 2;
        cout << "Foo: " << num << endl;
        mtx.unlock();
 
        //If you comment out the one thread will run several times in a row
        Usleep(50000);
    }
}
 
void bar(int& num, mutex& mtx)
{
    while (1)
    {
        //If you remove the lock synchronization will be lost
 
        mtx.lock();
        num -= 2;
        cout << "Bar: " << num << endl;
        mtx.unlock();
 
        Usleep(50000);
    }
}
 
int main()
{
    int num = 10;
    mutex mtx;
 
    thread t1(foo, ref(num), ref(mtx));
    thread t2(bar, ref(num), ref(mtx));
 
    t1.join();
    t2.join();
}
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