Rust compile-time assertions to ensure that invariants are met.
This crate is available on crates.io and can be used by adding the
following to your project's Cargo.toml
:
toml
[dependencies]
static_assertions = "0.2.2"
and this to your crate root:
```rust
extern crate static_assertions; ```
Use assert_eq_size!
to ensure two types are the same size:
```rust // Requires a label if in module scope asserteqsize!(byte; u8, u8);
fn func() { // If label-less, must be in a function to work asserteqsize!([u8; 4], u32);
// Supports unlimited arguments
assert_eq_size!([u8; 8], u64, (u32, u32), (u32, u16, u16), ...);
// Fails to compile
assert_eq_size!(u16, u64);
}
```
Use assert_eq_size_val!
to ensure two values are the same size:
```rust let x: u32 = 42; let y: u32 = 10; asserteqsize_val!(x, y, [0u8; 4]);
// Fails to compile asserteqsize_val!(x, 0u8); ```
Note: Both macros support multiple arguments and are not restricted by the recursion limit.
A constant expression can be ensured to evaluate to true
at compile-time.
The const_assert
and const_assert_eq
macros have the same scope and label
limitations as assert_eq_size
.
```rust // Supports constants const FIVE: usize = 5;
fn func() { const_assert!(1 + 1 == 2);
// Supports unlimited comma-separated conditions
const_assert!(4 > 3, 3 + 2 == FIVE);
// Fails to compile
const_assert!(2 != 2);
} ```
See issue #1 to read up on current limitations of this crate and how to currently overcome them.
This project is released under either:
at your choosing.