https://github.com/sunsided/ensure-uniform-type-rs

A compile-time check to ensure that a type uses uniform types across its fields.
https://github.com/sunsided/ensure-uniform-type-rs

procedural-macro rust

Last synced: about 2 months ago
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A compile-time check to ensure that a type uses uniform types across its fields.

• Host: GitHub
• URL: https://github.com/sunsided/ensure-uniform-type-rs
• Owner: sunsided
• License: eupl-1.2
• Created: 2024-06-15T14:16:05.000Z (12 months ago)
• Default Branch: main
• Last Pushed: 2024-06-15T14:39:43.000Z (12 months ago)
• Last Synced: 2025-03-09T08:51:53.533Z (3 months ago)
• Topics: procedural-macro, rust
• Language: Rust
• Homepage: https://crates.io/crates/ensure-uniform-type
• Size: 18.6 KB
• Stars: 0
• Watchers: 1
• Forks: 0
• Open Issues: 0
• Metadata Files:
  • Readme: README.md
  • Changelog: CHANGELOG.md
  • License: LICENSE.md

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README

        
# `#[ensure_uniform_type]`: Ensure uniform struct field types at compile-time

[![Crates.io](https://img.shields.io/crates/v/ensure-uniform-type)](https://crates.io/crates/ensure-uniform-type)

[![Crates.io](https://img.shields.io/crates/l/ensure-uniform-type)](https://crates.io/crates/ensure-uniform-type)

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[![docs.rs](https://img.shields.io/docsrs/ensure-uniform-type)](https://docs.rs/ensure-uniform-type/)

A compile-time check to ensure that a type uses uniform types across its fields.

An example use for this macro is to ensure that a struct `#[repr(C)]` layout can

be correctly mapped onto a slice of the (uniform) field type.

## Example

Assume the following type:

```rust

#[ensure_uniform_type]

pub struct Example

{

    /// First field

    x: T,

    // Different type

    offending: u32,

}

```

The above would fail to compile, instead giving the error:

```

error: Struct DifferentialDriveState has fields of different types. Expected uniform use of T, found u32 in field offending.

  --> src/differential_drive.rs:16:1

   |

16 | / /// A state of a differential drive robot, or differential wheeled robot.

18 | | #[ensure_uniform_type]

19 | | pub struct Example

...  |

37 | |     offending: u32,

38 | | }

   | |_^

```

By contrast, the following would compile without an error:

```rust

#[ensure_uniform_type]

pub struct Example

{

    x: T,

    not_offending: T,

}

```