What does static_cast do to a T&?

Question

So I asked this question and I was tinkering around with solving it via static_cast. (Incidentally it does solve the problem, I\'m just not sure if I understand

Answer 1

1. Yes, it is the same as int{...}, unless .front() returned a type that required a narrowing conversion. In that case, int(...) would be identical.

2. In the case of programmer error, static cast is marginally less likely to do something dangerous, like convert a pointer into an int than int(...).

Note eliminating the cast results in undefined behaviour as the front element is modified by the replace operation, and that could break std::replace.

I would use

template
std::decay_t copy_of(T&& t){return std::forward(t); }

myself here.

As for why this isn't working in MSVC...

MSVC helpfully takes situations where you cast a variable of type T to a T and proceeds to do nothing. This breaks your code.

There is a compiler flag (/Zc:rvalueCast) you can use to make MSVC no longer break your code.