Swift version 4.1 (swift-4.1-RELEASE) Target: x86_64-unknown-linux-gnu/usercode/main.swift:2:18: error: use of unresolved identifier 'floor' print("\(x) -> \(floor(x))") // 意図通り /usercode/main.swift:5:18: error: use of unresolved identifier 'floor' print("\(y) -> \(floor(y))") // 995.0 になって欲しい