Compare

Compares two blocks of memory byte by byte.

Module: Std::Memory

Signature

func Compare(lhs: *const opaque, rhs: *const opaque, length: uint) -> uint;

Parameters

Name	Type	Description
lhs	*const opaque	First block.
rhs	*const opaque	Second block.
length	uint	Number of bytes to compare.

Returns

uint — the index of the first byte that differs, or length if the two blocks are equal over all length bytes.

Description

Scans up to length bytes and reports where the blocks first diverge. A return value equal to length means the ranges are identical; any smaller value is the offset of the first mismatch.

TIP

This differs from C's memcmp, which returns a sign. Here, test for equality with Compare(a, b, n) == n.

Example

import Std::Memory::*;

func Equal(a: *opaque, b: *opaque, n: uint) -> bool {
    return Compare(a, b, n) == n;
}

See also

• Copy — duplicate a block of memory