async.cs

void Caller1(C c, I i)
{
    c.F1(); // No warning
    c.F2(); // CS4014: Because this call is not awaited, execution of the current method continues before the call is completed. Consider applying the 'await' operator to the result of the call.
    i.F3(); // No warning
}
 
async Task Caller2(C c, I i)
{
    c.F1(); // CS4014 
    c.F2(); // CS4014 
    i.F3(); // CS4014 
}
 
class C
{
    public Task F1()
    {
    }
 
    public async Task F2()
    {
    }
}
 
interface I
{
    /*async*/Task F3();
}