✨ cfg_table

一个简单的宏，在不同的编译目标上展开为不同的值。

恐慌

如果找不到匹配的值，此宏将在运行时引发恐慌。

示例

#[macro_use] extern crate cfg_table;

let var = cfg_table! {
    [all(target_os = "freebsd", target_pointer_width = "64", feature = "my-feature")] => 1337, // custom

    // common platforms
    win32 => 32,
    win64 => 64,
    linux32 => 32,
    linux64 => 64,
    macos32 => 32,
    macos64 => 64,

    // pointer widths
    32 => 1985,
    "32" => 1985,
    64 => 2003,
    "64" => 2003,

    _ => 123, // default value if nothing matches, this must be at the bottom
};

cfg_table! {
    win32 => {
        println!("You're on Windows 32-bit!");
    },

    win64 => {
        println!("You're on Windows 64-bit!");
    },

    _ => {
        panic!("What the heck is a \"Linux\"?");
    },
};