You define the __add__, __sub__, and __mul__ methods for the class, that’s how. Each method takes two objects (the operands of +/-/*) as arguments and is expected to return the result of the computation.
Yes, it says so in the C# Language Specification (highlighting by me): A null coalescing expression of the form a ?? b requires a to be of a nullable type or reference type. If a is non-null, the result of a ?? b is a; otherwise, the result is b. The operation evaluates b only … Read more
Comparing the lists with == requires elements to be comparable (denoted as Eq a). Prelude> :t (==[]) (==[]) :: (Eq a) => [a] -> Bool For example, [sin] == [] won’t work, since you can’t compare functions. It might seem stupid, but the type system must judge type of an expression without looking at its … Read more
You need to add where T : class to your method declaration, e.g. T Execute<T>() where T : class { By the way, as a suggestion, that generic wrapper doesn’t really add much value. The caller can write: MyClass c = whatever.Execute() as MyClass; Or if they want to throw on fail: MyClass c = … Read more
There’s no compilation error because + is a valid (albeit fairly useless) unary operator in the same way that – is: int x = +1; int y = -1; The relevant section in the Java Language Specification is Unary Plus Operator + (ยง15.15.3 ). It specifies that invoking the unary + operation results in Unary … Read more
<– is not a new Java operator (even though it may look like it), but there are 2 normal operators: < and — while (var2 <– var1) is the same as while(var2 < (–var1)), which can be translated to plain english as: decrement the var1 variable ( –var is a prefix decrementation, ie. decrement the … Read more
Python 3.x uses __truediv__ and __floordiv__. __div__ is 2.x-only.
This gives a overview: List of Domain operators: ! (Not), | (Or), & (And) List of Term operators: ‘=’, ‘!=’, ‘<=’, ‘<‘, ‘>’, ‘>=’, ‘=?’, ‘=like’, ‘=ilike’, ‘like’, ‘not like’, ‘ilike’, ‘not ilike’, ‘in’, ‘not in’, ‘child_of’ Usage: Input records: Record 1: Openerp Record 2: openerp Record 3: Opensource Record 4: opensource Record 5: Open … Read more