Macro hydroflow::var_expr

macro_rules! var_expr {
    () => { ... };
    (...$a:ident $(,)? ) => { ... };
    (...$a:expr  $(,)? ) => { ... };
    (...$a:ident, $( $b:tt )+) => { ... };
    (...$a:expr,  $( $b:tt )+) => { ... };
    ($a:ident $(,)? ) => { ... };
    ($a:expr  $(,)? ) => { ... };
    ($a:ident, $( $b:tt )+) => { ... };
    ($a:expr,  $( $b:tt )+) => { ... };
}

Variadic expressions (values) macro.

Creates a variadic tuple value from a list of expressions.

Create a variadic tuple value:

use variadics::var_expr;

let list = var_expr!(10, false, "foo");

assert_eq!(list, (10, (false, ("foo", ()))),)

Although this can be used as a pattern to unpack tuples, var_args! should be used instead:

// Ok...
let var_expr!(a, b, c) = var_expr!(10, false, "foo");
// Better:
let var_args!(a, b, c) = var_expr!(10, false, "foo");

assert_eq!(a, 10);
assert_eq!(b, false);
assert_eq!(c, "foo");

The “spread” (or “splat”) syntax ... can be used to concatenate variadics together:

let list_a = var_expr!(0.5, "foo");
let list_b = var_expr!(-5, false);
// Spread syntax:
let list_c = var_expr!(...list_a, ...list_b, "bar");
// Equals `var_expr!(0.5, "foo", -5, false, "bar)`.