| lib.rs |
A macro for defining `#[cfg]` if-else statements.
The macro provided by this crate, `cfg_if`, is similar to the `if/elif` C
preprocessor macro by allowing definition of a cascade of `#[cfg]` cases,
emitting the implementation which matches first.
This allows you to conveniently provide a long list `#[cfg]`'d blocks of code
without having to rewrite each clause multiple times.
# Example
```
cfg_if::cfg_if! {
if #[cfg(unix)] {
fn foo() { /* unix specific functionality */ }
} else if #[cfg(target_pointer_width = "32")] {
fn foo() { /* non-unix, 32-bit functionality */ }
} else {
fn foo() { /* fallback implementation */ }
}
}
# fn main() {}
``` |
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