structx 0.1.1

Simulating anonymous struct and named arguments in Rust.
Documentation 
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# Overview

This project provides simulation of anonymous struct and named arguments in
Rust, using proc macros `structx!{}`, `Structx!{}`, `#[named_args]` and
`args!{}`.

## Usage of this crate

Add the following in your Cargo.toml file:

```toml
[dependencies]
structx = "0.1"

[package.metadata.inwelling]
structx = true
```

Add the following in your .rs files:

```rust
use structx::*;
```

If you want to use named arguments, add the following:

```rust
use structx::named_args::*;
```

# Definitions and notations of anonymous structs

Anonymous structs are `struct`s without the needs of providing struct names.
However, the field names are mandatory. Anonymous structs are of the same type
if and only if they are composed of the same set of field names. The order of
fields are irrelevant.

## Value of anonymous structs

The notation of an anonymous struct's value is `structx!{}`.

## Examples of anonymous struct's values

```rust
let foo = structx!{ i: 3, b: true };
let bar = structx!{ x, y };
```

## Type of anonymous structs

The notation of an anonymous struct's type is `Structx!{}`.

## Examples of anonymous struct's types

```rust
fn foo( x: i32, y: i32 ) -> Structx!{ x: i32, y: i32 } {
    structx!{ x, y: y+1 }
}
```

## Traits derived for anonymous structs

Debug, PartialEq, Eq, PartialOrd, Ord, Hash.

```rust
let a = structx!{ width :  800, height: 600 };
let b = structx!{ height:  600, width : 800 };
let c = structx!{ width : 1024, height: 768 };
assert_eq!( a, b );
assert_ne!( a, c );
```

# Simulation of named arguments

At definition site, add attributes `#[named_args]` to functions.

```rust
#[named_args]
fn set_size( width: u32, height: u32 ) { todo!() }
```

At call site, wrap arguments with `args!{}`.

```rust
set_size( args!{ width: 1024, height: 768 });
```

# Caveat

## Reverse dependency

Collecting types and values of anonymous structs from downstream crates makes
crate structx depending on its users. Unfortunately this kind of
reverse-dependency is not known to cargo. As a result, the modifications of .rs
files which change types and values of anonymous structs will not cause
recompilation of crate structx, which it should.

To address this issue, simply do `cargo clean`, or more precisely,
`cargo clean --package structx` before running `cargo build`.

# License

Under Apache License 2.0 or MIT License, at your will.