Why does match keep temporary values in scope through arms?

[mbrubeck]

The rules about temporary lifetimes, especially in conditional expressions, are a bit inconsistent, but can't be changed significantly without breaking existing code. See this thread for some details:

While let borrow lifetime seems to be too long

Hello, By my reasoning, the two while let -loop headers in the program below should be equivalent, but the commented-out one causes a panic, as the borrowed value is not dropped by the time control enters the loop body. Or am I missing something here? This can be worked around by introducing an explicit inner let block, as shown in the code. Is there some reason to keep the value alive so long? After some googling, this seems to be connected to Non-Lexical Lifetimes development. Would this b…