Function bytesAsSlice [src]

Given a slice of bytes, returns a slice of the specified type backed by those bytes, preserving pointer attributes. If T is zero-bytes sized, the returned slice has a len of zero.

Prototype

pub fn bytesAsSlice(comptime T: type, bytes: anytype) BytesAsSliceReturnType(T, @TypeOf(bytes))

Parameters

T: type

Example

 test bytesAsSlice {
    {
        const bytes = [_]u8{ 0xDE, 0xAD, 0xBE, 0xEF };
        const slice = bytesAsSlice(u16, bytes[0..]);
        try testing.expect(slice.len == 2);
        try testing.expect(bigToNative(u16, slice[0]) == 0xDEAD);
        try testing.expect(bigToNative(u16, slice[1]) == 0xBEEF);
    }
    {
        const bytes = [_]u8{ 0xDE, 0xAD, 0xBE, 0xEF };
        var runtime_zero: usize = 0;
        _ = &runtime_zero;
        const slice = bytesAsSlice(u16, bytes[runtime_zero..]);
        try testing.expect(slice.len == 2);
        try testing.expect(bigToNative(u16, slice[0]) == 0xDEAD);
        try testing.expect(bigToNative(u16, slice[1]) == 0xBEEF);
    }
}

Source

  pub fn bytesAsSlice(comptime T: type, bytes: anytype) BytesAsSliceReturnType(T, @TypeOf(bytes)) {
    // let's not give an undefined pointer to @ptrCast
    // it may be equal to zero and fail a null check
    if (bytes.len == 0 or @sizeOf(T) == 0) {
        return &[0]T{};
    }

    const cast_target = CopyPtrAttrs(@TypeOf(bytes), .many, T);

    return @as(cast_target, @ptrCast(bytes))[0..@divExact(bytes.len, @sizeOf(T))];
}  