Type Function BoundedArray [src]

Alias for std.bounded_array.BoundedArray

A structure with an array and a length, that can be used as a slice. Useful to pass around small arrays whose exact size is only known at runtime, but whose maximum size is known at comptime, without requiring an Allocator. var actual_size = 32; var a = try BoundedArray(u8, 64).init(actual_size); var slice = a.slice(); // a slice of the 64-byte array var a_clone = a; // creates a copy - the structure doesn't use any internal pointers

Prototype

pub fn BoundedArray(comptime T: type, comptime buffer_capacity: usize) type

Parameters

T: typebuffer_capacity: usize

Example

 test BoundedArray {
    var a = try BoundedArray(u8, 64).init(32);

    try testing.expectEqual(a.capacity(), 64);
    try testing.expectEqual(a.slice().len, 32);
    try testing.expectEqual(a.constSlice().len, 32);

    try a.resize(48);
    try testing.expectEqual(a.len, 48);

    const x = [_]u8{1} ** 10;
    a = try BoundedArray(u8, 64).fromSlice(&x);
    try testing.expectEqualSlices(u8, &x, a.constSlice());

    var a2 = a;
    try testing.expectEqualSlices(u8, a.constSlice(), a2.constSlice());
    a2.set(0, 0);
    try testing.expect(a.get(0) != a2.get(0));

    try testing.expectError(error.Overflow, a.resize(100));
    try testing.expectError(error.Overflow, BoundedArray(u8, x.len - 1).fromSlice(&x));

    try a.resize(0);
    try a.ensureUnusedCapacity(a.capacity());
    (try a.addOne()).* = 0;
    try a.ensureUnusedCapacity(a.capacity() - 1);
    try testing.expectEqual(a.len, 1);

    const uninitialized = try a.addManyAsArray(4);
    try testing.expectEqual(uninitialized.len, 4);
    try testing.expectEqual(a.len, 5);

    try a.append(0xff);
    try testing.expectEqual(a.len, 6);
    try testing.expectEqual(a.pop(), 0xff);

    a.appendAssumeCapacity(0xff);
    try testing.expectEqual(a.len, 6);
    try testing.expectEqual(a.pop(), 0xff);

    try a.resize(1);
    try testing.expectEqual(a.pop(), 0);
    try testing.expectEqual(a.pop(), null);
    var unused = a.unusedCapacitySlice();
    @memset(unused[0..8], 2);
    unused[8] = 3;
    unused[9] = 4;
    try testing.expectEqual(unused.len, a.capacity());
    try a.resize(10);

    try a.insert(5, 0xaa);
    try testing.expectEqual(a.len, 11);
    try testing.expectEqual(a.get(5), 0xaa);
    try testing.expectEqual(a.get(9), 3);
    try testing.expectEqual(a.get(10), 4);

    try a.insert(11, 0xbb);
    try testing.expectEqual(a.len, 12);
    try testing.expectEqual(a.pop(), 0xbb);

    try a.appendSlice(&x);
    try testing.expectEqual(a.len, 11 + x.len);

    try a.appendNTimes(0xbb, 5);
    try testing.expectEqual(a.len, 11 + x.len + 5);
    try testing.expectEqual(a.pop(), 0xbb);

    a.appendNTimesAssumeCapacity(0xcc, 5);
    try testing.expectEqual(a.len, 11 + x.len + 5 - 1 + 5);
    try testing.expectEqual(a.pop(), 0xcc);

    try testing.expectEqual(a.len, 29);
    try a.replaceRange(1, 20, &x);
    try testing.expectEqual(a.len, 29 + x.len - 20);

    try a.insertSlice(0, &x);
    try testing.expectEqual(a.len, 29 + x.len - 20 + x.len);

    try a.replaceRange(1, 5, &x);
    try testing.expectEqual(a.len, 29 + x.len - 20 + x.len + x.len - 5);

    try a.append(10);
    try testing.expectEqual(a.pop(), 10);

    try a.append(20);
    const removed = a.orderedRemove(5);
    try testing.expectEqual(removed, 1);
    try testing.expectEqual(a.len, 34);

    a.set(0, 0xdd);
    a.set(a.len - 1, 0xee);
    const swapped = a.swapRemove(0);
    try testing.expectEqual(swapped, 0xdd);
    try testing.expectEqual(a.get(0), 0xee);

    const added_slice = try a.addManyAsSlice(3);
    try testing.expectEqual(added_slice.len, 3);
    try testing.expectEqual(a.len, 36);

    while (a.pop()) |_| {}
    const w = a.writer();
    const s = "hello, this is a test string";
    try w.writeAll(s);
    try testing.expectEqualStrings(s, a.constSlice());
}

Source

  pub fn BoundedArray(comptime T: type, comptime buffer_capacity: usize) type {
    return BoundedArrayAligned(T, @alignOf(T), buffer_capacity);
}  