Function span [src]

Takes a sentinel-terminated pointer and returns a slice, iterating over the memory to find the sentinel and determine the length. Pointer attributes such as const are preserved. [*c] pointers are assumed to be non-null and 0-terminated.

Prototype

pub fn span(ptr: anytype) Span(@TypeOf(ptr))

Example

 test span {
    var array: [5]u16 = [_]u16{ 1, 2, 3, 4, 5 };
    const ptr = @as([*:3]u16, array[0..2 :3]);
    try testing.expect(eql(u16, span(ptr), &[_]u16{ 1, 2 }));
    try testing.expectEqual(@as(?[:0]u16, null), span(@as(?[*:0]u16, null)));
}

Source

  pub fn span(ptr: anytype) Span(@TypeOf(ptr)) {
    if (@typeInfo(@TypeOf(ptr)) == .optional) {
        if (ptr) |non_null| {
            return span(non_null);
        } else {
            return null;
        }
    }
    const Result = Span(@TypeOf(ptr));
    const l = len(ptr);
    const ptr_info = @typeInfo(Result).pointer;
    if (ptr_info.sentinel()) |s| {
        return ptr[0..l :s];
    } else {
        return ptr[0..l];
    }
}  