根据传递给构造函数的参数，C++ 方法是否可以具有不同的返回类型？

Question

I have a template class in C++ that has a method that in theory should return a T (specific type) if a certain parameter is 1 (this parameter is not known until an object is constructed), and if the parameter is greater than 1 another instantiation of the class should be returned. Is there any easy way to do this?

Answer 1

Consider: You're assigning the return value of that function to some auto variable. The compiler needs to be able to decide what type that variable has to be... at compile time .

So no, there is no way to do it. You can use eg std::variant or std::any as return type, but you can't change return type through any runtime mechanics.

Answer 2

parameter is not known until an object is constructed..

answer is
Yes if above meant in static way
No if above meant in dynamic way

No code given above meant no useful way

Answer 3

(Sorry, cannot comment on anything yet)

You are not able to have one function that has different types of returns (would not fit the technical definition of a function anymore), but if you are able to check the parameter that you say might be == 1 or > 1 you could probably make a call to one of two different methods, each performing your desired operation for their respective cases.