error: main.swift:8:26: warning: will never be executed let hoge: CustomString = "fuga" ^ main.swift:8:26: note: a call to a never-returning function let hoge: CustomString = "fuga" ^ main.swift:4:14: warning: will never be executed self = "hoge" ^ main.swift:4:16: note: a call to a never-returning function self = "hoge" ^ main.swift:3:5: warning: will never be executed init(stringLiteral value: StringLiteralType) { ^ main.swift:3:5: note: a call to a never-returning function init(stringLiteral value: StringLiteralType) { ^ /usr/bin/swift[0x3f24d54] /usr/bin/swift[0x3f25096] /lib/x86_64-linux-gnu/libpthread.so.0(+0x11390)[0x7f46186b8390] [0x7f4618ae70e2] [0x7f4618ae70fa] [0x7f4618ae70fa] [0x7f4618ae70fa] [0x7f4618ae70fa] [0x7f4618ae70fa] [0x7f4618ae70fa] [0x7f4618ae70fa] [0x7f4618ae70fa] [0x7f4618ae70fa] [0x7f4618ae70fa] [0x7f4618ae70fa] [0x7f4618ae70fa] [0x7f4618ae70fa] [0x7f4618ae70fa] [0x7f4618ae70fa] [0x7f4618ae70fa] [0x7f4618ae70fa] [0x7f4618ae70fa] [0x7f4618ae70fa] [0x7f4618ae70fa] [0x7f4618ae70fa] [0x7f4618ae70fa] [0x7f4618ae70fa] [0x7f4618ae70fa] [0x7f4618ae70fa] [0x7f4618ae70fa] [0x7f4618ae70fa] [0x7f4618ae70fa] [0x7f4618ae70fa] [0x7f4618ae70fa] [0x7f4618ae70fa] [0x7f4618ae70fa] [0x7f4618ae70fa] [0x7f4618ae70fa] [0x7f4618ae70fa] [0x7f4618ae70fa] [0x7f4618ae70fa] [0x7f4618ae70fa] [0x7f4618ae70fa] [0x7f4618ae70fa] [0x7f4618ae70fa] [0x7f4618ae70fa] [0x7f4618ae70fa] [0x7f4618ae70fa] [0x7f4618ae70fa] [0x7f4618ae70fa] [0x7f4618ae70fa] [0x7f4618ae70fa] [0x7f4618ae70fa] [0x7f4618ae70fa] [0x7f4618ae70fa] [0x7f4618ae70fa] [0x7f4618ae70fa] [0x7f4618ae70fa] [0x7f4618ae70fa] [0x7f4618ae70fa] [0x7f4618ae70fa] [0x7f4618ae70fa] [0x7f4618ae70fa] [0x7f4618ae70fa] [0x7f4618ae70fa] [0x7f4618ae70fa] [0x7f4618ae70fa] [0x7f4618ae70fa] [0x7f4618ae70fa] [0x7f4618ae70fa] [0x7f4618ae70fa] [0x7f4618ae70fa] [0x7f4618ae70fa] [0x7f4618ae