func withVaList<R>(_: [CVarArgType], _: CVaListPointer -> R) Invoke f with a C va_list argument derived from args. Declaration func withVaList<R>(args: [CVarArgType], @noescape _ f: CVaListPointer -> R) -> R func withVaList<R>(_: VaListBuilder, _: CVaListPointer -> R) Invoke f with a C va_list argument derived from builder. Deprecated: it will be removed in Swift 3. Declaration func withVaList<R>(builder: VaListBuilder, @noescape _ f: CVaListPointer -> R) -> R