[unwind]

There is nothing "dynamic" about what I suggested. There is a real, concrete, static and compile-time known type at all times.

In this case it would be long. I fail to see the huge risk you're implying by operating upon a long-typed value without repeating the type name in the code.

    const auto pos_auto = ftell(fp);
    const long pos_long = ftell(fp);

I don't understand what you can do with 'pos_long' that would be dangerous doing with 'pos_auto' (again, disregarding I/O since then you typically have to know or cast).

[shrimp_emoji]

> again, disregarding I/O since then you typically have to know or cast

Thank you for answering for me!

[astrange]

`const long pos_long = ftell(fp);` contains a potential implicit case in the future if the return type of `ftell()` changes.

That's one reason type inference is safer than not inferring. Your program doesn't include semantics you didn't actually intend to be part of its meaning.

Also, I think lambdas would be annoying without it.