Crate cfg_iif

A macro for defining #[cfg] if-else functions.

The macro provided by this crate. Unlike cfg_if, cfg_iif can be used as a function, and can be used in a function.

Features

• minimum support rustc 1.56.1 (59eed8a2a 2021-11-01)

Example

Example 1: #[cfg()]

• a_iif is “unix” when a os is Unix at compile time:

use cfg_iif::cfg_iif;
let a_iif = cfg_iif!(#[cfg(Unix)] { "unix" } else { "not unix" });

• a_iif is “abc” when a feature is “has_abc” at compile time:

use cfg_iif::cfg_iif;
let a_iif = cfg_iif!(#[cfg(feature = "has_abc")] { "abc" } else { "not abc" });

• a_iif is “abc” when a feature is “has_abc” at compile time:

use cfg_iif::cfg_iif;
let mut a_iif = "";
cfg_iif!(
    #[cfg(feature = "has_abc")]
    {
        a_iif = "abc";
    }
);

Example 2: a short hand for a firendly cargo fmt

• a_iif is “abc” when a feature is “has_abc” at compile time:

use cfg_iif::cfg_iif;
let a_iif = cfg_iif!(feature = "has_abc" { "abc" } else { "not abc" });

• a_iif is “abc” when a feature is “has_abc” at compile time:

use cfg_iif::cfg_iif;
let mut a_iif = "";
cfg_iif!(feature = "has_abc" {
    a_iif = "abc";
});

Macros

cfg_iif

This macro provided by this crate. See crate documentation for more information.