小编dvn*_*yen的帖子

我跑来rustup update更新我的工具链并看到两个警告:

warning: tool `rustfmt` is already installed, remove it from `/Users/<username>/.cargo/bin`, then run `rustup update` to have rustup manage this tool.
warning: tool `cargo-fmt` is already installed, remove it from `/Users/<username>/.cargo/bin`, then run `rustup update` to have rustup manage this tool.

我按照警告信息中的说明操作,然后rustfmt再次尝试运行.我收到了错误

error: toolchain 'stable-x86_64-apple-darwin' does not have the binary rustfmt`

出了什么问题,我该如何解决？

在挖掘C++项目时,我遇到了C++ new运算符的奇怪用法:

int arr[5];
ClassA* a = new(arr) ClassA();

你能帮我理解这个语法吗？

这是/etc/cloud/cloud.cfgUbuntu云16.04映像的内容：

# The top level settings are used as module
# and system configuration.

# A set of users which may be applied and/or used by various modules
# when a 'default' entry is found it will reference the 'default_user'
# from the distro configuration specified below
users:
   - default

# If this is set, 'root' will not be able to ssh in and they
# will get a message to login instead as the above $user (ubuntu) …