# Switch Statement For Rust
*A simple macro to emulate a `switch` statement in Rust.*
[![crates.io](https://img.shields.io/crates/v/switch_statement.svg)](https://crates.io/crates/switch_statement)
[![Docs](https://docs.rs/switch_statement/badge.svg)](https://docs.rs/switch_statement/)
[![License](https://img.shields.io/badge/license-MIT-blue.svg)](LICENSE)
## Description
The `switch!` macro looks similar to `match`. But instead of pattern matching,
each left-hand-side expression is interpreted as an expression instead of a
pattern. One use case for this is to match against constants joined with
bitwise OR. The output of the macro is a `match` with `if` guards.
## Example
```rust
const A: u32 = 1 << 0;
const B: u32 = 1 << 1;
const C: u32 = 1 << 2;
fn flag_string(input: u32) -> &'static str {
switch! { input;
A => "A",
// bitwise OR
A | B => "A and B",
A | B | C => "A and B and C",
B | C => "B and C",
_ => "other"
}
}
```
The above code expands to:
```rust
const A: u32 = 1 << 0;
const B: u32 = 1 << 1;
const C: u32 = 1 << 2;
fn flag_string(input: u32) -> &'static str {
match input {
v if v == A => "A",
v if v == A | B => "A and B",
v if v == A | B | C => "A and B and C",
v if v == B | C => "B and C",
_ => "other"
}
}
```