static import std.file;
import std.typecons : tuple;

// prepare test file
auto testFile = std.file.deleteme();
scope(failure) printf("Failed test at line %d\n", __LINE__);
std.file.write(testFile, "1 2\n4 1\n5 100");
scope(exit) std.file.remove(testFile);

File f = File(testFile);
scope(exit) f.close();

auto expected = [tuple(1, 2), tuple(4, 1), tuple(5, 100)];
uint i;
foreach (e; f.byRecord!(int, int)("%s %s"))
{
    assert(e == expected[i++]);
}