Macro proc_bitfield::with_bits

with_bits!() { /* proc-macro */ }

Returns an anonymous bitfield with a single field modified, without creating a bitfield struct.

Usage example: returning a modified bitfield with with_bits!

As for bits!, the field’s type T can be specified by prepending T @ to the bit range, or additionally by casting the new value with as T. However, in this example it can be inferred.

let a = 0x1234_u16;

// A single field spanning the entire bitfield, using an unbounded range:
// NOTE: In this case, the bitfield's storage type needs to be specified by appending `as T`
assert_eq!(with_bits!(a as u16, .. = 0xFFFF), 0xFFFF); // Bits 0 to 31

// Multi-bit field, specified using an inclusive range:
assert_eq!(with_bits!(a, 0..=3 = 0xF), 0x123F);        // Bits 0 to 3

// Multi-bit field, specified using an exclusive range:
assert_eq!(with_bits!(a, 4..8 = 0xF), 0x12F4);         // Bits 4 to 7

// Multi-bit field specified using its start bit and length:
assert_eq!(with_bits!(a, 8; 4 = 0xF), 0x1F34);         // Bits 8 to 11

// Single-bit field, specified using an inclusive range:
assert_eq!(with_bits!(a, 12..=12 = 1), 0x1234);        // Bit 12

// Single-bit field, specified using an exclusive range:
assert_eq!(with_bits!(a, 13..14 = 1), 0x3234);         // Bit 13

// Single-bit field, specified using its start bit and a length of 1:
assert_eq!(with_bits!(a, 14; 1 = 1), 0x5234);          // Bit 14

// Single-bit boolean flag, specified using a single bit position:
assert_eq!(with_bits!(a, 15 = true), 0x9234);          // Bit 15