Linspace fix for high ranks

[cliffburdick]

Fix linspace static_assert failing when NUM_RC > 2

The static_assert in LinspaceOp::operator() checked sizeof...(indices) == NUM_RC, but the operator is always rank 2 when NUM_RC > 1. With 3+ firsts/lasts entries, the operator is called with 2 indices but the assert expected 3+, causing a compile error.

[copy-pr-bot]

This pull request requires additional validation before any workflows can run on NVIDIA's runners.

Pull request vetters can view their responsibilities here.

Contributors can view more details about this message here.

[cliffburdick]

/build

[greptile-apps]

Greptile Summary

This PR fixes a compile error in LinspaceOp::operator() where a static_assert compared the number of variadic indices against NUM_RC (the number of rows or columns), but the operator is always rank 2 (i.e., called with 2 indices) when NUM_RC > 1. The fix correctly replaces NUM_RC with Rank(), which returns 1 when NUM_RC == 1 and 2 otherwise.

Key changes:

• include/matx/generators/linspace.h: Change static_assert(sizeof...(indices) == NUM_RC, ...) to static_assert(sizeof...(indices) == Rank(), ...), correctly matching the actual rank of the operator (always 1 or 2, never NUM_RC when NUM_RC > 2).
• test/00_operators/GeneratorTests.cu: Adds three new test cases covering NUM_RC = 3 (axis=0), NUM_RC = 3 (axis=1), and NUM_RC = 4 (axis=0), verifying both Size() dimensions and per-element values.
• docs_input/api/creation/operators/linspace.rst: Adds a documentation example referencing the new test-4 case.

The fix is minimal, correct, and Rank() is already defined as static inline constexpr so it is valid to use inside a static_assert.

Confidence Score: 5/5

This PR is safe to merge — it is a minimal, well-reasoned bug fix with no logic changes beyond the corrected static_assert.

The root cause is clearly identified and the fix (Rank() instead of NUM_RC) is the correct constant to use. Rank() is already a static constexpr method, so it is valid inside static_assert. No P0 or P1 issues were found. Three new test cases verify the fixed behavior end-to-end, and documentation was updated accordingly.

No files require special attention.

Important Files Changed

Filename	Overview
include/matx/generators/linspace.h	Single-line fix: static_assert now uses Rank() (always 1 or 2) instead of NUM_RC, correctly matching the number of indices the operator is called with.
test/00_operators/GeneratorTests.cu	Adds three comprehensive test cases for NUM_RC=3 (axis=0 and axis=1) and NUM_RC=4 (axis=0), covering Size() and per-element value correctness.
docs_input/api/creation/operators/linspace.rst	Adds a documentation literalinclude block linking the new test-4 example for high-rank linspace usage.

Flowchart

%%{init: {'theme': 'neutral'}}%%
flowchart TD
    A["linspace(firsts, lasts, count, axis)"] --> B["LinspaceOp<T, NUM_RC> constructed"]
    B --> C{"NUM_RC == 1?"}
    C -- Yes --> D["Rank() = 1"]
    C -- No --> E["Rank() = 2 (regardless of NUM_RC)"]
    D --> F["operator()(idx0)\nstatic_assert: sizeof...(indices) == Rank()"]
    E --> G["operator()(idx0, idx1)\nstatic_assert: sizeof...(indices) == Rank()"]
    G --> H{"axis_ == 0?"}
    H -- Yes --> I["firsts_[idx1] + steps_[idx1] * idx0"]
    H -- No --> J["firsts_[idx0] + steps_[idx0] * idx1"]
    F --> K["firsts_[0] + steps_[0] * idx0"]

Loading

_{Reviews (2): Last reviewed commit: "Added examples" | Re-trigger Greptile}