function call in for loop condition

I got into an argument with a co-worker today about this snippet:


for (int i = 0; i < foo(); i++)
{
}

I told him that he shouldn't put the foo() function in the termination check of that for loop. He said that the compiler actually assigns the result of foo() to a variable and then sticks that in where foo() is at. I said that we can't rely on that. We're working in C++ on .NET. Who's right?

if you were using C with a decent compiler (or even gcc), you could mark the function as a pure function and the compiler would automatically save the result.