variadic_from 0.59.0

Variadic from.
Documentation 
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43

// variadic_from_trivial.rs

//! This example demonstrates the use of the `VariadicFrom` derive macro.
//! It allows a struct with a single field to automatically implement the `From` trait
//! for multiple source types, as specified by `#[ from( Type ) ]` attributes.

#[ cfg(not(all(feature = "enabled", feature = "type_variadic_from", feature = "derive_variadic_from"))) ]
fn main() {}
#[ cfg(all(feature = "enabled", feature = "type_variadic_from", feature = "derive_variadic_from")) ]
fn main() 
{
  use variadic_from ::exposed :: *;
  use variadic_from_meta ::VariadicFrom;

  // Define a struct `MyStruct` with a single field `value`.
  // It derives common traits and `VariadicFrom`.
  #[ derive( Debug, PartialEq, Default, VariadicFrom ) ]
  struct MyStruct 
  {
  value: i32,
 }

  // Example with a tuple struct
  #[ derive( Debug, PartialEq, Default, VariadicFrom ) ]
  struct MyTupleStruct(i32);

  // Test `MyStruct` conversions
  let got: MyStruct = 10.into();
  let exp = MyStruct { value: 10 };
  assert_eq!(got, exp);

  let got_tuple: MyTupleStruct = 50.into();
  let exp_tuple = MyTupleStruct(50);
  assert_eq!(got_tuple, exp_tuple);

  dbg!(exp);
  //> MyStruct {
  //>   value: 10,
  //> }

  dbg!(exp_tuple);
  //> MyTupleStruct( 50 )
}