Bug: Crash when adding a labeled vector, using the Swift binding

[intitni]

Describe the bug

I modified the test in the package to run in an XCTestCase, and it crashes when adding a labeled vector at the line index.add(label: 42, vector: vectorA[...])

The package crashes at index.hpp line 889 with Thread 1: EXC_BAD_ACCESS (code=1, address=0x488)

Thread 1 Queue : com.apple.main-thread (serial)
#0	0x00000001183a6d80 in unum::usearch::sorted_buffer_gt<unum::usearch::index_gt<unum::usearch::index_punned_dense_metric_t, unsigned int, unsigned int, unum::usearch::aligned_allocator_gt<char, 64ul>, unum::usearch::memory_mapping_allocator_gt<1ul> >::candidate_t, unum::usearch::index_gt<unum::usearch::index_punned_dense_metric_t, unsigned int, unsigned int, unum::usearch::aligned_allocator_gt<char, 64ul>, unum::usearch::memory_mapping_allocator_gt<1ul> >::compare_by_distance_t, unum::usearch::aligned_allocator_gt<unum::usearch::index_gt<unum::usearch::index_punned_dense_metric_t, unsigned int, unsigned int, unum::usearch::aligned_allocator_gt<char, 64ul>, unum::usearch::memory_mapping_allocator_gt<1ul> >::candidate_t, 64ul> >::clear() at /Users/x/Developer/Projects/usearch/include/usearch/index.hpp:889
#1	0x00000001183a6678 in unum::usearch::index_gt<unum::usearch::index_punned_dense_metric_t, unsigned int, unsigned int, unum::usearch::aligned_allocator_gt<char, 64ul>, unum::usearch::memory_mapping_allocator_gt<1ul> >::add(unsigned int, unum::usearch::span_gt<char const>, unum::usearch::add_config_t) at /Users/x/Developer/Projects/usearch/include/usearch/index.hpp:1783
#2	0x00000001183a63bc in unum::usearch::index_gt<unum::usearch::index_punned_dense_metric_t, unsigned int, unsigned int, unum::usearch::aligned_allocator_gt<char, 64ul>, unum::usearch::memory_mapping_allocator_gt<1ul> >::add_result_t unum::usearch::index_punned_dense_gt<unsigned int, unsigned int>::add_<float>(unsigned int, float const*, unum::usearch::add_config_t, std::__1::function<bool (char const*, unsigned long, char*)> const&) at /Users/x/Developer/Projects/usearch/include/usearch/index_punned_dense.hpp:373
#3	0x00000001183a61c8 in unum::usearch::index_gt<unum::usearch::index_punned_dense_metric_t, unsigned int, unsigned int, unum::usearch::aligned_allocator_gt<char, 64ul>, unum::usearch::memory_mapping_allocator_gt<1ul> >::add_result_t unum::usearch::index_punned_dense_gt<unsigned int, unsigned int>::add_<float>(unsigned int, float const*, std::__1::function<bool (char const*, unsigned long, char*)> const&) at /Users/x/Developer/Projects/usearch/include/usearch/index_punned_dense.hpp:450
#4	0x000000011834aabc in unum::usearch::index_punned_dense_gt<unsigned int, unsigned int>::add(unsigned int, float const*) at /Users/x/Developer/Projects/usearch/include/usearch/index_punned_dense.hpp:258
#5	0x000000011834a984 in -[USearchIndex addSingle:vector:] at /Users/x/Developer/Projects/usearch/objc/USearchObjective.mm:126
#6	0x00000001183b0e50 in closure #1 in USearchIndex.add(label:vector:) at /Users/x/Developer/Projects/usearch/swift/Index+Sugar.swift:16
#7	0x0000000107bb0e7c in partial apply for closure #1 in USearchIndex.add(label:vector:) ()
#8	0x000000019d3c3d9c in ArraySlice.withContiguousStorageIfAvailable<τ_0_0>(_:) ()
#9	0x0000000107bb0d18 in USearchIndex.add(label:vector:) at /Users/x/Developer/Projects/usearch/swift/Index+Sugar.swift:15
#10	0x0000000107b49858 in Test.testUnit() at /Users/x/Developer/Projects/usearch/swift/Test.swift:18

I checked the CI output, actually, the test was not running.

warning: 'usearch': found 1 file(s) which are unhandled; explicitly declare them as resources or exclude from the target
    /Users/runner/work/usearch/usearch/swift/Test.swift

[0/1] Planning build
Building for debugging...
[1/3] Emitting module USearchTests
[2/3] Compiling USearchTests Test.swift
[2/3] Linking USearchPackageTests
Build complete! (7.68s)
Test Suite 'All tests' started at 2023-06-27 10:08:35.166
Test Suite 'All tests' passed at 2023-06-27 10:08:35.168.
	 Executed 0 tests, with 0 failures (0 unexpected) in 0.000 (0.002) seconds

Steps to reproduce

1. wrap the testUnit() in swift/Test.swift in class Test: XCTestCase {}.
2. run the test

Expected behavior

No crash.

USearch version

v0.19.0

Operating System

macOS 13.4 (22F66)

Hardware architecture

Arm

Which interface are you using?

Other bindings

Contact Details

No response

Is there an existing issue for this?

• I have searched the existing issues

Code of Conduct

• I agree to follow this project's Code of Conduct

[ashvardanian]

Interesting! @intitni, can you please submit a PR with that test change, I will investigate in the next couple of days.

[ashvardanian]

I see. The problem is we have slightly different behavior depending on how close the programming language is to a systems language. In C/C++/Rust, we request the user use reserve before add-ing new vectors. We do it behind the curtains in Python, JS, and Java, assuming the users won't notice the performance penalty. With Swift and Objective-C being between the two worlds, I forgot to implement any of the variants.

Which do you think makes more sense, @intitni? I assume it would make sense to add a reserve function to Objective-C and Swift bindings.

[intitni]

I think it's fine to add a reserve function.

[ashvardanian]

Fixed and released in v0.19.1. @intitni, please let us know if you find any other issues or have feature requests 🤗